Publications
| Title | Abstract | Year(sorted ascending) Filter | PMID Filter |
|---|
| bound calcium and force development in skinned cardiac muscle bundles: effect of sarcomere length. | there is evidence that the steep ascending limb of the force-length curve in cardiac muscle (frank-starling relation) is based on a length-dependence of myofilament ca2+ sensitivity. previous work from this laboratory has indicated that in the sarcomere length range corresponding to the ascending limb of the cardiac force length curve (1.7 to 2.3 microns) the ca2+-troponin c affinity is length-dependent. in this study ca2+ binding to chemically skinned bovine cardiac muscle bundles was measured ... | 1988 | 3221407 |
| dynamics of the interventricular septum and ventricular free walls during regional ischaemia in open-chest dogs. | the significance of ischaemia of the left ventricular (lv) and right ventricular (rv) free walls for the dynamics of the interventricular septum (ivs) and the right ventricle was examined in open-chest dogs. left ventricular and rv ischaemia reduced stroke volume similarly, by 11.2 +/- 1.4% and 11.2 +/- 2.4%, respectively. the dynamics of myocardial segment lengths (sl), recorded in the lv and rv free walls and the ivs, differed. during lv ischaemia, end-diastolic sl (edsl) and systolic shorteni ... | 1988 | 3227889 |
| effect of substrate-free albumin on perfused rat kidney function. | the effect of varying concentrations of substrate-free albumin (sfa) in the absence of exogenous substrate was investigated in the isolated perfused rat kidney. consistent with starling relationship, there was a progressive decrease in glomerular filtration rate (gfr), from 778 +/- 36 to 41 +/- 17 microliters/min.g, and a progressive increase in fractional sodium reabsorption (%tna+), from 31.1 +/- 0.9 to 82.6 +/- 2.3%, when the mean sfa concentration in the perfusate was increased from 3 to 10 ... | 1988 | 3231893 |
| [intracranial hemodynamics in arterial hypertension (the renal model)]. | the changes of intracranial hemodynamics were studied at the early stage of vasorenal arterial hypertension in 7 rabbits. during first 4-5 weeks of the hypertension development, the ap increased to 170 mm hg which was followed by a drop in the blood flow by 15% in the cortex and by 19% in white matter. the blood flow increment in response to inhalation of co2 lowered from initial 120% to 106% in the cortex and from 126% to 109% in white matter. the data on the brain tissue impedance suggested an ... | 1988 | 3246286 |
| [clinical and experimental studies on the pathogenesis in pregnancy induced hypertension]. | placental ischemia is one of the etiological factors of pregnancy induced hypertension (pih), however, the pathogenesis of placental and renal ischemia has not been clarified. the purposes of this investigation are (1) to clarify the fetomaternal hemodynamic changes in pih and the influence of maternal postural change on fetomaternal hemodynamics, measured by thermodilution method, impedance cardiography and pulsed doppler method during pregnancy, (2) to provide to relationship between intrauter ... | 1988 | 3251961 |
| identity of gonadotropin-releasing hormone in passerine birds: comparison of gnrh in song sparrow (melospiza melodia) and starling (sturnus vulgaris) with five vertebrate gnrhs. | gonadotropin-releasing hormone (gnrh) was detected in the brains of passerine birds, a recently evolved and diverse avian group. the molecular forms of gnrh in two species of birds under breeding conditions were deduced using methods of hplc and immunology. the brain extracts of song sparrows (melospiza melodia) contained a form of gnrh identified as chicken i gnrh-like peptide by its hplc elution pattern and cross-reactivity with four antisera. in contrast, starling (sturnus vulgaris) brain ext ... | 1988 | 3282980 |
| control of left ventricular function during acceleration-induced blood volume shifts. | peripheral pooling of blood was produced in chronically instrumented, sedated dogs (n = 7) by subjecting them to a +2 gz force (along their spinal axis) for 3 min. the acceleratory force was then quickly removed, thereby mobilizing blood toward the thoracic cavity. left ventricular volume, calculated from ultrasound measurements of major and minor axes and wall thickness, increased (p less than 0.05) from 21.7 +/- 3.6 ml (diastolic, mean +/- s.e.m.) and 14.1 +/- 3.3 ml (systolic) during the peri ... | 1988 | 3291846 |
| effects of altered left atrial pressure on pulmonary vascular pressure-flow relationships. | we studied the effects of changes in pulmonary capillary wedge pressure (pcwp) on the slope (incremental resistance) and the extrapolated pressure intercept (pi) of the mean pulmonary artery pressure (pap)-cardiac output (co) relationship. multipoint plots of pap against co were obtained in intact anesthetized dogs. group 1 consisted of six dogs entirely in west zone 3 and group 2 of four dogs with mixed west zone 2-3. the four conditions studied were the following: 1) fixed low pcwp, 2) fixed h ... | 1988 | 3293470 |
| parameter extraction from heart rate and arterial blood pressure variability signals in dogs for the validation of a physiological model. | the paper describes an automatic procedure for improving the extraction of parameters in heart rate (hr) and arterial blood pressure (abp) beat-to-beat variability signals. auto- and cross-spectral analysis of such signals is carried out through parametric models and the distribution of the power of the spectra and the phase relationships are compared in various physiological situations induced in the dogs via drug infusion or surgical interventions which do influence the control mechanisms of h ... | 1988 | 3335123 |
| hyperkinesis without the frank-starling mechanism in a nonischemic region of acutely ischemic excised canine heart. | to determine the essential mechanism of increased systolic wall motion, i.e., hyperkinesis, in a nonischemic region (nir) during acute ischemia, we simultaneously evaluated global and regional function of the excised, cross-circulated canine left ventricle connected to a volume servo pump before and after coronary occlusion. regional areas were determined with pairs of orthogonal subendocardial sonomicrometers in the ischemic region (ir) and nir. after coronary occlusion with left ventricular en ... | 1988 | 3338135 |
| correlation between the linearized frank-starling relationship and myocardial energetics in the ejecting heart. effect of unprotected and protected global ischemia. | previous studies noted augmented postischemic myocardial oxygen consumption as a subtle indicator of ischemic injury in the isovolumically contracting left ventricle. the present study was done to determine if the linear relationship between oxygen utilization and stroke work present in the ejecting heart would facilitate compartmentalization of this increased oxygen consumption into resting and working metabolic demands. therefore, 18 canine hearts instructed for computerized acquisition of ins ... | 1988 | 3343853 |
| interaction of plasma colloid osmotic pressure and joint fluid pressure across the endothelium-synovium layer: significance of extravascular resistance. | fluid exchanges between blood and a synovial joint cavity across two membranes in series--synovial capillary wall (fenestrated) and synovial intima (modified connective tissue). the relation between transsynovial absorption of intraarticular krebs solution (flow qs) and plasma colloid osmotic pressure pi p was investigated in rabbit knees perfused at constant blood pressure. intraarticular pressure pj was independently controlled. linear relations between transsynovial flow and plasma colloid os ... | 1988 | 3343936 |
| microvascular exchange and interstitial volume regulation in the rat: model validation. | a dynamic mathematical model is formulated and used to describe the distribution and transport of fluid and plasma proteins between the circulation, interstitial space of skin and muscle, and the lymphatics in the rat. two descriptions of transcapillary exchange are investigated: a homoporous "starling model" and a heteroporous "plasma leak model." parameters used in the two hypothetical transport mechanisms are determined based on statistical fitting procedures between simulation predictions an ... | 1988 | 3344829 |
| role of barometric pressure in pulmonary fluid balance and oxygen transport. | to examine the role of barometric pressure in high-altitude pulmonary edema, we randomly exposed five unanesthetized chronically instrumented sheep with lung lymph fistulas in a decompression chamber to each of three separate conditions: hypobaric hypoxia, normobaric hypoxia, and normoxic hypobaria. a combination of slow decompression and/or simultaneous adjustment of inspired po2 provided three successive stages of simulated altitudes of 2,600, 4,600, and 6,600 m during which hemodynamics and l ... | 1988 | 3356658 |
| evaluation of starling forces in the equine digit. | a pump-perfused extracorporeal digital preparation was used to evaluate blood flow, arterial pressure, venous pressure, isogravimetric capillary filtration coefficient, capillary pressure, and vascular compliance in six normal horses. from these data, pre- and postcapillary resistances and pre- and postcapillary resistance ratios were determined. vascular and tissue oncotic pressures were estimated from plasma and lymph protein concentrations, respectively. by use of the collected and calculated ... | 1988 | 3378993 |
| filtration coefficient and osmotic reflection coefficient to albumin in rabbit submandibular gland capillaries. | 1. the isolated perfused submandibular salivary gland of the rabbit has been used in order to make estimates of the filtration coefficient (kf) and reflection coefficient (sigma d) of the capillary wall to albumin. 2. an isogravimetric preparation was used and in paired experiments the value for kf obtained in glands perfused with albumin-krebs solution, 0.96 +/- 0.086 (mean +/- s.e. of mean) ml min-1 mmhg-1 100 g-1, was not significantly different from that in blood-perfused glands, 0.90 +/- 0. ... | 1988 | 3392669 |
| mechanics and energetics of overstretch: the relationship of altered left ventricular volume to the frank-starling mechanism and phosphorylation potential. | isovolumic perfused rat hearts containing an intraventricular balloon were used to assess the effects of incremental balloon volumes on developed pressure, oxygen consumption, coronary flow, phosphorylation potential obtained by p-31 nuclear magnetic resonance, wall thickness obtained by two-dimensional echocardiography, and diastolic wall stress. three phases in developed pressure were noted: (1) volumes from 0 to 150 microliter resulted in a continuous increase in developed pressure; (2) with ... | 1988 | 3400567 |
| quantitative morphological analysis of the sensory epithelium of the starling and pigeon basilar papilla. | several features of bird basilar papilla morphology were quantitatively studied in the starling and the pigeon in order to attempt a structure-function correlation. we confirmed and quantified several findings from earlier studies, but also obtained results contradictory to previous reports. the greatest discrepancies concerned the pattern of hair cell orientation. by including the results from other investigations, we describe a 'typical' avian basilar papilla and on this basis the specializati ... | 1988 | 3403387 |
| fluid filtration coefficient of isolated goat lungs was unchanged by endotoxin. | the starling fluid filtration coefficient (kf) of blood-perfused excised goat lungs was examined before and after infusion of escherichia coli endotoxin. kf was calculated from rate of weight gain as described by drake et al. [am. j. physiol. 234 (heart circ. physiol. 3): h266-h274, 1978]. these calculations were made twice during base line and then at hourly intervals for 5 h after infusion of 5 mg (approximately 250 micrograms/kg) of e. coli endotoxin or after injection of oleic acid (47 micro ... | 1988 | 3403430 |
| indirect estimate of perimicrovascular pressure rise in edema in isolated zone 1 lung. | to determine how liquid accumulation affects extra-alveolar perimicrovascular interstitial pressure, we measured filtration rate under zone 1 conditions (25 cmh2o alveolar pressure, 20 or 10 cmh2o vascular pressure) in isolated dog lung lobes in which all vessels were filled with autologous plasma. in the base-line condition, starting with normal extra-alveolar water content, filtration rate decreased by about one-half over 1 h as edema liquid slowly accumulated. we repeated each experiment afte ... | 1988 | 3403477 |
| forward diastolic flow in pulmonary artery induced by right atrial contraction of pig hearts. | to study whether right atrial contraction can forward blood into the pulmonary artery during diastole, blood volume was expanded in anesthetized open-chest pigs until mean right atrial pressure was 13-20 mmhg (range). in the control situation, blood flow in the pulmonary artery was only observed during ventricular systole. forward diastolic pulmonary artery flow, coinciding with right atrial contraction, was observed when diastolic pulmonary artery pressure was reduced during selectively increas ... | 1988 | 3407786 |
| myocardial depression in hyperdynamic endotoxemia. | the presence of myocardial depression is difficult to assess in most animal models of septic shock caused by hypovolemia. we studied endotoxemia in fluid-resuscitated conscious sheep. they underwent chronic instrumentation with pulmonary artery, arterial, and left atrial catheters. after 1 week of recovery, 1.5 micrograms/kg of endotoxin (lps) was administered intravenously over a period of 30 min. one group of nine sheep stayed on baseline fluids (2 ml/kg/h of ringer's lactate), while a second ... | 1988 | 3197261 |
| effect of tracheal smooth muscle tone on collapsibility of immature airways. | to test the influence of smooth muscle tone on extremely immature airways, tracheal segments (n = 19) were excised from premature lambs at 114-121 days gestation and mounted in a chamber filled with krebs solution. inflation (si) and collapsing (sc) compliance were determined by altering transmural pressure from 30 to 0 torr and -30 to 0 torr, respectively, both during control (c) and after acetylcholine (ach) administration (experimental, e). flow (v = 2-15 l/min) was then introduced through th ... | 1988 | 3170433 |
| [recent physiologic and pathophysiologic studies in heart function in the perinatal period]. | recent investigations of the cardiac output in fetal lambs have shown that left ventricular output reaches nearly exclusively the upper circulation of the body (head, neck, forelegs) via the ascending aorta. right ventricular output supplies predominantly the descending aorta via the ductus arteriosus. increasing afterload results in reductions of stroke volumes in the fetus as well as in the neonate. the frank-starling-mechanism is only weakly developed in lambs before and after birth. immediat ... | 1988 | 3188706 |
| influence of smooth muscle tone and longitudinal tension on the collapsibility of immature airways. | mechanical properties and pressure-flow relationships of tracheae excised from very premature lambs were studied in a plethysmograph. control (group i) data revealed the tracheae to be extremely compliant, collapsible airways, with an inflation compliance (si) of 0.033 (+/- 0.004 se) mmhg-1, collapsing compliance (sc) of 0.026 (+/- 0.001 se) mmhg-1, and pressure-flow relationships similar to those of a starling resistor. acetylcholine administration (group ii) lowered both si, 0.026 (+/- 0.003 s ... | 1988 | 3194153 |
| distensibility of hepatic venous resistance sites and consequences on portal pressure. | hepatic venous resistance was measured in cats anesthetized with pentobarbital sodium during changes in hepatic blood flow and in inferior vena cava (ivc) pressure, in an attempt to explain the variable and partial transmission of pressure from ivc to portal vein. problems with earlier explanations based on a "vascular waterfall" or a "starling resistor" are discussed. our data and previously published data can be explained by the hypothesis that hepatic venous resistance decreases as the resist ... | 1988 | 3348424 |
| continuous arteriovenous hemofiltration: an in vitro simulation and mathematical model. | in vitro and mathematical models of continuous arteriovenous hemofiltration (cavh) have been developed. human erythrocytes resuspended in normal saline containing 5% bovine albumin were used to perfuse the circuit from a gravity driven pressure source. membrane hydraulic permeability was observed to decline from 31.2 x 10(-5) +/- 11.9 x 10(-5) cm/(min.mm hg) before use to 12.3 x 10(-5) +/- 3.3 x 10(-5) (mean +/- sd) after use. this fall occurred during the first one to two hours whether perfused ... | 1988 | 3367559 |
| myocardial dysfunction in sepsis. | the characteristic hemodynamic profile of human septic shock consists of a normal or elevated cardiac index and a decreased systemic vascular resistance index. when a patient with septic shock has a low cardiac index, concomitant hypovolemia is usually present. within 48 hours of the onset of septic shock, most patients develop marked dilatation of both ventricles, depressed ejection fractions, and alterations of the frank-starling and diastolic pressure-volume relationships; stroke volume typic ... | 1989 | 2647229 |
| model for the physics and physiology of fluid administration. | this article describes a model designed to provide an understanding of fluid flow in intravenous systems and human subjects. experiments were developed which demonstrate that the model can represent common clinical situations. the model depicts physical devices as ideal resistors, pressure sources, and flow sources. the patient's venous system is depicted as a combination of ordinary and starling resistors. for flows between 0 and 300 ml/hr, both physical devices and patients are adequately repr ... | 1989 | 2656923 |
| 7-heteroaryl-1,2,3,5-tetrahydroimidazo[2,1-b]quinazolin -2(1h)-one derivatives with cardiac stimulant activity. | a series of 7-heteroaryl-1,2,3,5-tetrahydroimidazo[2,1-b]quinazolin++ +-2 (1h)-ones was synthesized and evaluated in dogs for cardiac stimulant activity. compounds were obtained by a palladium-catalyzed cross-coupling reaction between a heteroarylzinc chloride and a 7-iodo-1,2,3,5-tetrahydroimidazo [2,1-b]quinazolin-2(1h)-one or by cyclization of an n-[(2-aminophenyl)methyl]glycinate with cyanogen bromide. compared to the parent ring system (3), introduction of a 2,6-dimethylpyridin-3-yl (6), 2, ... | 1989 | 2769678 |
| the regulation of the ratio of the cardiopulmonary blood volume to stroke volume in sheep. | volume expansion with dextran was used in unanaesthetised sheep to investigate the mechanisms which are responsible for keeping the ratio of the cardiopulmonary blood volume to stroke volume (cpfi) constant under physiological conditions. for animals with heart rates lower than 80, active pulmonary vasoconstriction was mainly responsible for the regulation obtained with volume expansion, while the starling mechanism was responsible for keeping the ratio constant for animals with heart rates abov ... | 1989 | 2482132 |
| progressive coronary vasoconstriction during 25 hours of myocardial preservation in vitro impairs functional capacity following preservation. | we have developed perfusion techniques for preserving rat hearts for 25 h and have quantified haemodynamic function after preservation to establish the relation between coronary vascular resistance during preservation and the quality of postpreservation pump function. thirteen rat hearts underwent hypothermic (8 degrees c), low-pressure (15 mmhg) perfusion with an hyperosmotic (385 mosm/l) crystalloid preservation buffer for 25 h. during this period, the coronary flow rate decreased from 1.12 +/ ... | 1989 | 2635942 |
| is a decrease in plasma oncotic pressure enough to explain the edema of pregnancy? | the balance of fluid across capillaries is given by the starling equation. because the plasma protein concentration (one of its components) is decreased in pregnancy, we decided to explore the question as to whether hypoproteinemia with intact protein mass (produced by blood volume expansion) or hypoproteinemia with decreased total protein mass (produced by removal of circulating proteins) alters the oncotic pressure differences across capillaries. we calculated the oncotic pressure difference o ... | 1989 | 2603920 |
| differentiation of various cardiovascular drugs by means of specific myocardial and vascular load tests. experiments at the isolated perfused heart. | a new method is described for examining the contractile function of myocardium and coronary vasculature in the isolated perfused, electrically stimulated guinea-pig and rat heart which is suitable for investigation of cardiovascular drugs. the criterion used for functional efficiency of myocardium and coronary vasculature is--in addition to the usual evaluation of cardiac force and coronary flow in steady-state--the reaction of the heart to perfusion pressure changes: abrupt increase of the perf ... | 1989 | 2624601 |
| cellular mechanism of the modulation of contractile function by coronary perfusion pressure in ferret hearts. | 1. isovolumic left ventricular pressure was measured at various coronary arterial pressures in langendorff-perfused ferret hearts. the concentrations of phosphorus-containing metabolites were measured using 31p nuclear magnetic resonance (nmr). intracellular free calcium concentration ([ca2+]i), was measured with 19f nmr in a group of hearts that were loaded with the calcium indicator 5f-bapta. 2. developed pressure increased when coronary arterial pressure was raised from the control value of 8 ... | 1989 | 2607438 |
| [estimation of the filtration variables in the rat lung]. | the filtration variables, filtration coefficient (k), perimicrovascular pressure (ppmv) and reflection coefficient (sigma) were estimated independently in previous reports using the starling equation or the micropuncture method. we estimated these variables simultaneously. we measured filtration rate by a gravimetric method in isolated rat lung lobes in zone 1 conditions (alveolar pressure = 20 cmh2o) at two vascular pressures, pvasc = 15 or 8 cmh2o and perfused the lobes with plasma containing ... | 1989 | 2615069 |
| brain cholinesterase activity of nestling great egrets, snowy egrets and black-crowned night-herons. | inhibition of brain cholinesterase (che) activity in birds is often used to diagnose exposure or death from organophosphorus or carbamate pesticides. brain che activity in the young of altricial species increases with age; however, this relationship has only been demonstrated in the european starling (sturnus vulgaris). brain che activity of nestling great egrets (casmerodius albus) collected from a colony in texas (usa) increased significantly with age and did not differ among individuals from ... | 1989 | 2761008 |
| blood-nerve transfer of albumin and its implications for the endoneurial microenvironment. | blood-nerve transfer of plasma albumin was studied by measuring the permeability coefficient-surface area (ps) product of the blood-nerve barrier (bnb) to 125i-albumin in rat sciatic nerve using the i.v. bolus injection method. the calculated ps was 6.3 +/- 0.5 (s.e.m.) x 10(-7) ml.g-1.s-1. this value is smaller by more than an order of magnitude of that measured for sucrose and confirms the relative impermeance of the bnb to blood-borne solutes. from a review of the available evidence, it is co ... | 1989 | 2765909 |
| pyruvate-enhanced phosphorylation potential and inotropism in normoxic and postischemic isolated working heart. near-complete prevention of reperfusion contractile failure. | bioenergetic and hemodynamic consequences of cellular redox manipulations by 0.2-20 mm pyruvate were compared with those due to adrenergic stress (0.7-1.1 microm norepinephrine) using isolated working guinea-pig hearts under the conditions of normoxia, low-flow ischemia, and reperfusion. 5 mm glucose (+ 5 u/l insulin) + 5 mm lactate were the basal energy-yielding substrates. to stabilize left ventricular enddiastolic pressure, ventricular filling pressure was held at 12 cmh2o under all condition ... | 1989 | 2707262 |
| the hemoglobins of the adult blackbird (turdus merula, passeriformes). the sequence of the major (hba) and minor component (hbd). | the blood of the adult blackbird contains one major hemoglobin component (hba = alpha a2, beta 2, ca. 80%) and one minor one (hbd = alpha d2 beta 2, ca. 20%). the hb-components were separated by fplc on a tsk sp-5 pw column, and eluted with a linear nacl gradient, while the globin chains were purified on a cation exchange (cm-cellulose). tryptic peptides from the globin chains were separated by hplc on an rp-2 lichrosorb column. the complete amino acid sequence was determined by automatic edman ... | 1989 | 2757791 |
| clinical and physiologic significance of local tissue renin-angiotensin systems. | increasing and compelling evidence continues to amass that favors the existence of local tissue renin-angiotensin systems. all renin-angiotensin system components have been demonstrated in kidney, brain, arteries, adrenals, and other organs. favoring its clinical importance are direct demonstration of its components in tissues; dissociation between hemodynamic and structural effects of renin-angiotensin system inhibition; evidence for local modulating roles with other humoral, autocrine/paracrin ... | 1989 | 2690610 |
| [central and peripheral circulation in patients after orthotopic transplantation of the heart]. | heart transplantation in human medicine is a unique model which makes it possible to study circulatory changes in complete denervation of the heart. the authors examined repeatedly the central and peripheral haemodynamics after orthotopic heart transplantation (ots) in 11 patients (11 males, 1 female; mean age 44 +/- 4 years) following an interval of three months to four years after the operation. the values of central haemodynamics at rest varied in the majority within the normal range. after a ... | 1989 | 2662579 |
| interplay among cardiac chambers. left and right ventricular performance during changes in contractility, afterload and during simultaneous atrio-ventricular contraction. | 1. only a slight increase in stroke volume is observed during a selective left-sided inotropic stimulation of the in situ pig heart. decreased left ventricular preload during left-sided inotropic stimulation reduces activation of the frank-starling mechanism and hence explains the rather small increase in stroke volume. we suggest that left-sided inotropic stimulation redistributes blood from the pulmonary circulation toward the systemic circulation causing a fall in pulmonary artery pressure an ... | 1989 | 2668474 |
| cardiopulmonary dysfunction in a feline septic shock model: possible role of leukotrienes. | the aim of the present study was to explore the possible involvement of leukotrienes (lts) in the development of cardiopulmonary dysfunction in experimental septic shock. sepsis was induced in anesthetized cats by infusion of liver escherichia coli bacteria. one series (n = 6) was pretreated with diethylcarbamazine (dec), a 5-lipooxygenase inhibitor; another series (n = 7) was pretreated with fpl 55712, a ltc4-d4 antagonist; and a third series (n = 8) served as septic controls. after 2 hr of bac ... | 1989 | 2676231 |
| effects of small changes in carotid sinus pressure on renal haemodynamics and function in dogs. | 1. in dogs anaesthetized with chloralose and artificially ventilated, the carotid sinuses were vascularly isolated and perfused with arterial blood. mean aortic pressure was held constant at 111 +/- 2 mmhg (mean +/- s.e.m., n = 18) by means of a pressure bottle connected to the aorta and a starling resistance. both vagus nerves were sectioned in the neck and propranolol hydrochloride (1 mg kg-1 h-1) or atenolol (0.5-4 mg kg-1 h-1) was administered. the left and right renal blood flows were measu ... | 1989 | 2621595 |
| 2(1h)-quinolinones with cardiac stimulant activity. 3. synthesis and biological properties of 6-imidazol-1-yl derivatives. | a series of 6-imidazol-1-yl-8-methyl-2(1h)-quinolinones was synthesized and evaluated for cardiac stimulant activity in dogs. the majority of compounds were prepared from an appropriate 6-imidazol-1-yl-2(1h)-quinolinone precursor or by sulfuric acid catalyzed cyclization of an n-(4-heteroarylphenyl)-3-ethoxypropenamide. introduction of a range of 5-substituents into 6-(2,4-dimethylimidazol-1-yl)-8-methyl-2(1h)-quinolinone (1) reduced inotropic activity in anesthetized dogs (percentage increase i ... | 1989 | 2544726 |
| effect of increased alpha-adrenergic activity on the blood pressure/cardiac output relationship in dogs. | the relationship between mean aortic blood pressure (map) and cardiac output (co) was examined in anaesthesized, open-chest dogs during variations in pre-load with and without alpha-adrenergic stimulation with phenylephrine. when phenylephrine increased map to 200 mmhg, co fell greatly and could not be increased by volume expansion. left ventricular ultrasonic measurements and pressure recordings showed that the frank-starling mechanism was maximally activated. during vena cava obstruction co an ... | 1989 | 2564244 |
| 2(1h)-quinolinones with cardiac stimulant activity. 2. synthesis and biological activities of 6-(n-linked, five-membered heteroaryl) derivatives. | a series of 6-(n-linked, five-membered heteroaryl)-2(1h)-quinolinone derivatives was synthesized and evaluated for cardiotonic activity. most compounds were prepared by sulfuric acid catalyzed cyclization of an n-(4-heteroarylphenyl)-3-ethoxypropenamide or by condensation of a 2-amino-5-heteroarylbenzaldehyde or -acetophenone derivative with the ylide derived from triethyl phosphonoacetate. in anesthetized dogs, 6-imidazol-1-yl-8-methyl-2(1h)-quinolinone (3; 25 micrograms/kg) produced a greater ... | 1989 | 2537423 |
| immunohistochemical localization of corticotropin-releasing factor in selected brain areas of the european starling (sturnus vulgaris) and the song sparrow (melospiza melodia). | corticotropin-releasing factor (crf) was localized in the brains of two passerine species, the european starling (sturnus vulgaris) and the song sparrow (melospiza melodia), by means of immunohistochemistry. the hypothalamic distribution of this peptide in these species includes a complex of immunoreactive perikarya observed in the paraventricular nucleus (pvn), in both its medial and lateral divisions. nerve fibers were also seen running from these areas to the anterior median eminence (ame) wh ... | 1989 | 2787697 |
| the influence of ventricular extrasystoles and postextrasystoles on cardiovascular dynamics in anesthetized dogs. | the influence of ventricular extrasystoles and postextrasystoles on cardiovascular dynamics were assessed in terms of maximum rate of rise of left ventricular pressure (max dp/dt), ascending aortic flow, left ventricular stroke volume, and left ventricular end-diastolic transverse dimension in anesthetized dogs. a single ventricular extrasystole, two and three consecutive ventricular extrasystoles (couplet and triplet) were induced by applying mechanical stimulation to the surface of the right v ... | 1989 | 15236059 |
| photoperiodic time measurement during the termination of photorefractoriness in the starling (sturnus vulgaris l.). | groups of photorefractory male european starlings have been kept under nanda-hamner ld schedules ranging from ld 6:6 to ld 6:54 for about 6 weeks. subsequently, when transferred to ld 13:11, all birds of groups ld 6:18 and ld 6:42 went through a complete cycle of testicular growth and regression. furthermore, they carried out a postnuptial molt, indicating that they have been able to terminate photorefractoriness under these ld schedules. in contrast, no positive responses could be detected in g ... | 1989 | 2767409 |
| photoperiodic control of the development of the lhrh neurosecretory system of european starlings (sturnus vulgaris) during puberty and the onset of photorefractoriness. | the development of the reproductive system was studied in juvenile starlings during the acquisition of photosensitivity, the attainment of sexual maturation after photostimulation and the subsequent onset of photorefractoriness, using immunohistochemistry for lhrh and radioimmunoassay measurements of hypothalamic, pituitary and plasma hormone concentrations. the first stage of sexual development induced by exposure of photorefractory immature starlings to short days (8 h light:16 h darkness; 8l: ... | 1989 | 2671239 |
| relative pitch perception in the european starling (sturnus vulgaris): further evidence for an elusive phenomenon. | relative pitch perception in animals has been difficult to demonstrate. this failing is due in part to stimulus sets that make an absolute pitch solution viable. in experiment 1, starlings failed to acquire a discrimination that could be solved only on the basis of relative pitch. in experiment 2, starlings were trained on a smaller set of pitch patterns, for which both absolute and relative pitch solutions were available, then tested with three series of unreinforced probe stimuli. series 1 ass ... | 1989 | 2708939 |
| incidence of toxoplasma infection in a population of european starlings sturnus vulgaris from central england. | a sample of european starlings, sturnus vulgaris, culled from a communal roost in a city in central england, was examined for infection with toxoplasma. eleven (8%) of 133 birds were confirmed as infected after horizontal passage of brain homogenate through mice. serological examination, using the indirect and direct agglutination tests, proved unsatisfactory for screening starlings for toxoplasma infection. if the proportion of starlings infected with toxoplasma in this sample is representative ... | 1989 | 2604457 |
| physiological constraint on feeding behavior: intestinal membrane disaccharidases of the starling. | animals clearly choose what they eat and can even choose among chemically different sugars. the physiological and biochemical mechanisms that constrain feeding choices are largely unknown. in this study, european starlings (sturnus vulgaris) preferred mixture solutions of d-glucose plus d-fructose to equimolar (double molar caloric value) solutions of sucrose. intubation feeding of sucrose did not increase blood glucose levels. sucrose is a useless energy source for these birds because they lack ... | 1989 | 2916126 |
| song acquisition in photosensitive and photorefractory male european starlings. | we tested the ability of 1-year-old european starlings (sturnus vulgaris) to acquire songs while in different physiological states. photorefractory males, with low testosterone levels, learned songs as completely and as accurately as photosensitive males in full reproductive condition. this indicates that song acquisition in 1-year-old males does not depend on high levels of androgens. the ability to learn songs during the nonbreeding season may reflect the high song output of potential tutors t ... | 1990 | 2286369 |
| seasonal shifts in odor acuity by starlings. | a passerine bird, the european starling sturnus vulgaris, demonstrated a seasonal ability to respond to odor cues. cardiac conditioned responses were most evident when birds were in breeding condition. once birds were in nonbreeding condition, responding to odors all but ceased. for birds in breeding condition, threshold sensitivity to the odor cyclohexanone was comparable to levels reported for nonpasserine birds (0.3% vapor saturation or 3.778 x 10(14) molecules/ml). in contrast, the threshold ... | 1990 | 2391467 |
| muscarinic cholinergic receptors in the songbird and quail brain: a quantitative autoradiographic study. | in order to clarify the neuroanatomical basis for postulated muscarinic cholinergic control of a wide array of physiological processes in birds, the distribution of muscarinic cholinergic receptors in the brain of three avian species was investigated by quantitative autoradiography. the species consisted of two passerines (songbirds), the european starling (sturnus vulgaris) and the song sparrow (melospiza melodia), and one galliform, the japanese quail (coturnix coturnix japonica). [3h]n-methyl ... | 1990 | 2229474 |
| relation between capillary pressure and vascular tone over the range from maximum dilatation to maximum constriction in cat skeletal muscle. | an attempt was made to assess, from a large sample (n = 567), the normal level of hydrostatic capillary pressure (pc) in resting skeletal muscle and the extent of pc regulation as effected by strictly graded activation of metabolic and adrenergic control mechanisms over the entire physiological range of vascular tone. with the use of a new whole-organ technique, pc towards the venous end of the capillary was continuously recorded at constant arterial pressure (100 mmhg) and under simultaneous ob ... | 1990 | 2275407 |
| responses to changes in filling and contractility of indices of human left ventricular mechanical performance. | 1. beat-by-beat indices of contractility for assessment of inotropic effects in a given subject were studied using pacing with beta-adrenergic blockade, in eight patients undergoing routine left heart catheterization. a catheter-tip manometer was sited in the left ventricle and an electromagnetic velocity transducer was mounted further back on the same catheter so that it was sited in the ascending aorta. 2. the maximum rate of rise of left ventricular pressure (dplv/dtmax), and of aortic veloci ... | 1990 | 1972191 |
| atriopeptin 24 regulates myocardial function via frank-starling mechanism in conscious dogs. | recent studies have shown that the infusion of atriopeptins decreases blood volume because of the diuresis and also because of changes in vascular volume. in dogs chronically instrumented for the measurement of left ventricular pressure and internal left ventricular diameter, infusion of atriopeptin 24 (500 ng.kg-1.min-1 for 1 h), steady-state plasma levels of 6,000 pg/ml resulted in 5.9 +/- 1.7% decrease in left ventricular (lv) end-diastolic diameter (edd) from 34.7 +/- 2.3 mm (p less than 0.0 ... | 1990 | 2137297 |
| variation and correlation in human fetal umbilical doppler velocities with fetal breathing: evidence of the cardiac-placental connection. | doppler velocity waveforms in the human fetal umbilical vein and artery were analyzed during episodes of fetal breathing. heart rate, systolic and diastolic velocities were measured from the umbilical artery waveform. diastolic velocity varied the most with a mean (+/- sd) coefficient of variation of 16.0% +/- 5.0%. the coefficient of variation of systolic velocity was 7.8% +/- 2.4% and of heart rate was 5.0% +/- 1.8%. we also found that umbilical arterial flow was related to umbilical venous fl ... | 1990 | 2256484 |
| iodide and albumin kinetics in normal canine wrists and knees. | the clearance rates of free iodide and of radioiodinated serum albumin were measured in the knee and wrist joints of 9 normal adult dogs. iodide clearance from the knee was 3 times greater than that from the wrist. in contrast, radioiodinated serum albumin clearance from the knee was only slightly greater than that from the wrist. interpreted as respective indices of effective synovial plasma flow and lymphatic drainage, these values indicate that the filtration fraction is normally greater in m ... | 1990 | 2302270 |
| the effects of increasing mean arterial pressure on left ventricular output in newborn lambs. | we developed a preparation in which the mean arterial pressure of the newborn lamb is varied with little change in left ventricular preload. seven lambs underwent balloon atrial septostomy and were instrumented with vascular catheters, an electromagnetic flow transducer on the aorta, and a balloon occluder on the aorta. four different preload conditions were established by volume infusion or withdrawal. aortic flow was measured continuously during gradual occlusion of the aorta. curves relating ... | 1990 | 2364497 |
| inhibition of hypoxic pulmonary vasoconstriction by increased left atrial pressure in dogs. | to further explore the mechanism of hypoxic pulmonary vasoconstriction, we studied the mean pulmonary arterial pressure (ppa)/left atrial pressure (pla) relationship at fixed cardiac index (q) and the ppa/q relationship at several levels of fixed pla in pentobarbital sodium-anesthetized dogs ventilated alternately in hyperoxia [fraction of inspired o2 (fio2) 0.4 or 1.0] and in hypoxia (fio2 0.1). in all experimental conditions, ppa/q plots were linear with extrapolated pressure intercepts (pi) n ... | 1990 | 2375417 |
| stretch-induced increase in the ca2+ sensitivity of myofibrillar atpase activity in skinned fibres from pig ventricles. | the increase in force development in the heart with increase in end-diastolic pressure (frank-starling mechanism) has been ascribed to an increase in contractile responsiveness of the myofibrils to calcium. we now show that this calcium sensitization is also associated with an increase in calcium responsiveness of the myofibrillar atpase. thus, at submaximal ca activation (pca 6.0), the atpase activity of skinned fibres from pig right ventricles is increased from 57.9 +/- 4.4% to 70.6 +/- 4.4% o ... | 1990 | 2139931 |
| hormones as regulators of pancreatic secretion in man. | at the beginning of the century, pavlov suggested that the pancreas was exclusively controlled by the nervous reflex mechanisms. in 1902, bayliss & starling published their experiments on secretin and claimed that the nervous regulation is 'superfluous and improbable'. in the following decades, especially after the discovery of cck, it was generally held that exocrine pancreatic secretion is regulated mainly by hormones. the present summary clearly demonstrates the importance of the cholinergic ... | 1990 | 2124994 |
| role of mixed-function oxidases and non-protein sulfhydryl content in [14c]-2-chloro-4-acetotoluidide binding to liver and kidney in starlings. | the compound 2-chloro-4-acetotoluidide (cat) is highly toxic to many avian species, including the starling. in our earlier work, we demonstrated the covalent binding of radioactivity from [14c]-cat to liver and kidneys of the starling. in the present study, the effects of inducers of mixed-function oxidase (mfo) and non-protein sulfhydryl (npsh) depletor on the total and covalent binding of [14c]-cat radioactivity to liver and kidney of the starling were examined. the total and covalently bound ... | 1990 | 2084182 |
| evaluation of equine digital starling forces and hemodynamics during early laminitis. | a carbohydrate overload model was used in 8 horses to evaluate starling forces and hemodynamics of the digit during the prodromal stage of acute laminitis. a pump-perfused extracorporeal digital preparation was used to evaluate blood flow, arterial pressure, venous pressure, capillary pressure, isogravimetric capillary filtration coefficient, osmotic reflection coefficient, and vascular compliance. from these data, pre- and postcapillary resistances and pre- to postcapillary resistance ratios we ... | 1990 | 2085218 |
| auditory duration discrimination in the european starling (sturnus vulgaris). | auditory duration discrimination was studied in the european starling (sturnus vulgaris, n = 3) using a go/nogo-procedure. acoustic signals were presented by the method of constant stimuli. duration discrimination limens (ddls) were determined using signal detection theory (threshold criterion d' = 1.8). weber fractions delta t/t = 0.23 for reference durations of between 800 and 100 ms, respectively. the ddls for reference durations of 400 and 200 ms did not differ from those of 800 ms. there wa ... | 1990 | 2212285 |
| solute-coupled liquid absorption from the pleural space. | the occurrence of a solute-coupled absorption of liquid from the pleural space was studied by measuring in anesthetized rabbits the volume of liquid of the right pleural space 1 h after injecting into it 2 ml of ringer solution or of ringer with an inhibitor of a na(+)-cl- coupled transport or of the na+/k+ pump. volume collected after ringer was 1.56 +/- 0.08 ml. initial volume being 2.2 ml, net absorption rate was 0.64 ml/h. volume collected after disulfonic stilbene (0.1 mm) or bumetanide (0. ... | 1990 | 2218104 |
| differences in the recovery of right and left ventricular function after ischaemic arrest and cardioplegia. | differential susceptibility of right (rv) and left (lv) ventricles to plain ischaemia and the contribution of cardioplegia in reducing the ischaemic damage was evaluated in a sheep model of cardiopulmonary bypass. sheep (n = 16) were equally divided for the two protocols of the study. each sheep served as its own control. rv and lv functions were studied and compared by plotting ventricular function curves (starling and sarnoff). the mathematical centre of mass (com) for each curve was computed ... | 1990 | 2223120 |
| transperitoneal fluid dynamics in rabbit liver. | the peritoneal cavity of 18 anesthetized spontaneously breathing supine rabbits was opened through a midline section. one or two hollow capsules (surface area 0.8 cm2) were glued to the exposed liver surface, filled with whole or 25% diluted plasma, and connected to a transducer and a graduated pipette. various hydraulic pressures (pcap) were set in the capsule; at each pcap the liquid flow per unit surface area (v/s) between the disse's interstitial space and the capsule was measured from the r ... | 1990 | 2228874 |
| studies of myocardial protection in the immature heart. i. enhanced tolerance of immature versus adult myocardium to global ischemia with reference to metabolic differences. | this study compares the metabolism and functional responses of adult and immature hearts to a standard ischemic insult. ten adult dogs (25 to 27 kg) and 10 puppies (6 to 10 weeks old) underwent 45 minutes of aortic clamping on bypass. preoperative and postoperative ventricular performance (starling curves), biochemical factors, and water content were measured. global ischemia in adults produced a 30% mortality rate (3/10) and low output syndrome in survivors (33% recovery of stroke work index). ... | 1990 | 2246910 |
| effect of endotoxin administration on equine digital hemodynamics and starling forces. | using a pump-perfused extracorporeal isolated digital preparation, the effects of a 30-minute infusion of either saline solution (control) or endotoxin on equine digital hemodynamics and microvascular function were determined. digital blood flow and arterial, venous, and capillary pressures were recorded at 15-minute intervals for 150 minutes. from these data, total vascular resistance and pre- and postcapillary resistances were calculated. isogravimetric capillary filtration coefficient, vascul ... | 1990 | 2240793 |
| effects of abdominal pressure on venous return: abdominal vascular zone conditions. | the effects of changes in abdominal pressure (pab) on inferior vena cava (ivc) venous return were analyzed using a model of the ivc circulation based on a concept of abdominal vascular zone conditions analogous to pulmonary vascular zone conditions. we hypothesized that an increase in pab would increase ivc venous return when the ivc pressure at the level of the diaphragm (pivc) exceeds the sum of pab and the critical closing transmural pressure (pc), i.e., zone 3 conditions, but reduce ivc veno ... | 1990 | 2076989 |
| local and global function of the right ventricle in a canine model of pulmonary microembolism and oleic acid edema: influence of ventilation with peep. | right ventricular (rv) dysfunction may occur due to increased rv afterload and, hence, might also contribute to the decrease in cardiac output following institution of peep in patients with adult respiratory distress syndrome (ards). to test this hypothesis, the authors examined the influence of peep on local and global rv function in 12 anesthetized dogs with experimental ards (eards) induced by pulmonary microembolization with glass beads and oleic acid. local rv function was analyzed in the r ... | 1990 | 2240686 |
| right-left ventricular balance in implanted electrically powered artificial hearts. | an electrohydraulic total artificial heart (ehtah), using an interatrial shunt (ias) for right-left heart balance, was evaluated in acute, in vivo, open-chested calves. the ehtah system demonstrated physiologic autoregulation with starling-like responsiveness to preload. output varied from 4 to 9 l/min, as right atrial pressure increased from 3 to 15 mmhg. device output was minimally influenced by afterload. the efficacy of an ias to balance the ehtah was demonstrated over a wide range of preloa ... | 1990 | 2252680 |
| early onset of increased transcapillary albumin escape in awake diabetic rats. | alteration in transcapillary albumin escape rate (teralb) is an indicator of changes in macromolecular movement at the capillary filtering bed, which can change the balance of starling forces for fluid movement from the vasculature to the interstitium and has an impact on volume homeostasis. teralb can be affected by morphological changes in the capillary membrane and/or alterations in the starling forces driving larger solutes across the capillary membrane via convection. previous studies have ... | 1990 | 2142657 |
| resistance of descending vasa recta to the transport of water. | the effect of varying intracapillary oncotic pressure on the rate of transcapillary volume flux in microperfused descending vasa recta (dvr) was studied during furosemide diuresis in the munich-wistar rat. at the papillary base, plasma protein concentration and hydraulic pressure were 5.7 +/- 0.1 g/dl and 11.7 +/- 0.7 mmhg in nonperfused dvr, respectively, and 5.6 +/- 0.1 g/dl and 9.4 +/- 0.4 mmhg in nonperfused ascending vasa recta (avr), respectively. these results demonstrate that the papilla ... | 1990 | 1699435 |
| cardiac dysfunction in a rat model of chronic bacteremia. | cardiac function was examined in vivo and in vitro in rats to determine if cardiac dysfunction could be demonstrated in a nonlethal model of infection. bacteremic rats (n = 6) had a subcutaneous polymicrobial abscess produced via repeated inoculations of an encapsulated foreign body with escherichia coli, bacteroides fragilis, and staphylococcus aureus while control rats (n = 6) had the same subcutaneous, encapsulated foreign body (an inflammatory focus) but were not inoculated with bacteria. ca ... | 1990 | 2192813 |
| effects of acutely impaired regional function on remote myocardial wall motion and blood flow in the canine left ventricle studied by coronary occlusion and hypoxic perfusion. | the aim was to examine whether regional myocardial dysfunction has a significant effect on the wall motion and blood flow in remote non-ischaemic regions. | 1990 | 2386988 |
| starling resistor versus compliance. which explains the zero-flow pressure of a dynamic arterial pressure-flow relation? | arterial pressure at zero flow (pz = 0) that is higher than venous pressure (pv) in dynamic pressure-flow relations has been explained by the presence of an arteriolar starling resistor (sr) mechanism (i.e., vascular waterfall) or the discharge of vascular capacitance. to determine which was predominant, i studied in vivo hind limbs of 18 anesthetized dogs in which femoral arteries were cannulated with in-line electromagnetic flow probes to measure inflow (qin), pv was controlled, and collateral ... | 1990 | 2364491 |
| forces involved in transcapillary fluid movement in exercising cat skeletal muscle. | average capillary pressure (pc) close to the venous end (fluid equilibrium point) of the exchange vessels (denoted pc,v), arterial (pa) and venous pressure, and the rate of net transcapillary fluid flux were continuously recorded in sympathectomized muscle during 30 min of graded exercise and for 30 min in the post-exercise period. regional changes in colloid osmotic pressure (pi pl) and total osmolality in plasma, the latter reflecting work-induced interstitial hyperosmolality, were measured at ... | 1990 | 2267951 |
| a new method for estimating filtration variables in isolated zone 1 rat lung. | the filtration variables, k (filtration coefficient), ppmv (perimicrovascular pressure) and sigma (reflection coefficient), were estimated independently in previous reports using the starling equation or the micropuncture method. we used matrix algebra to estimate these variables simultaneously. we measured filtration rate (q) by a gravimetric method in isolated rat lung lobes in zone 1 conditions (alveolar pressure = 20 cmh2o) at two vascular pressures, pvasc = 15 or 18 cm h2o and perfused the ... | 1990 | 2353356 |
| left ventricular hypertrophy: dissociation of structural and functional effects by therapy. | the heart is one of the major target organs that becomes secondarily involved with the unrelenting and progressive vascular disease of essential hypertension. as a result of this increasing afterload that is imposed upon the left ventricle, the ventricular chamber adapts structurally and functionally. structural changes involve an increase in muscle mass that is achieved through left ventricular hypertrophy (in a manner similar to the arteriolar changes demonstrated by increased thickening). unl ... | 1991 | 1839347 |
| a two-dimensional morphometry-based model of interstitial and transcapillary flow in rabbit synovium. | the synovial lining of a joint is a layer of specialized connective tissue, containing fenestrated capillaries, that regulates the volume and composition of fluid in the joint cavity. the hydraulic conductance of the synovial lining and of the plasma-to-cavity pathway is increased by high intra-articular pressures (iap greater than 9 cmh2o) and this is accompanied by an increase in the interstitial pathway's area/pathlength ratio. in order to assess the contribution of the altered pathway geomet ... | 1991 | 1768416 |
| renal sodium retention in the nephrotic syndrome. | where do the experiments on rat kidneys exposed to puromycin leave us in attempting to evaluate further the pathophysiology of oedema in human nephrotic syndrome? they cannot be considered conclusive. the arguments favouring an intrinsic abnormality in the kidney as a major factor in sodium retention, rather than this being a secondary response to humoral and neural influences stimulated by changes in actual or perceived plasma volume, would be strengthened by experiments using another animal mo ... | 1991 | 1818554 |
| [turdus merula l. as a proper host of capillaria ovopunctata (nematoda, capillariidae)]. | biometrical analysis of four morphometric characters of male and female specimens of capillaria ovopunctata parasitizing in sturnus vulgaris, erithacus rubecula, turdus philomelos and turdus merula, i.e. length of body, oesophagus, number of stichocytes or length of spicula and vulvar appendage respectively was carried out. it has been proved, that characters of females c. ovopunctata parasitizing in t. merula significantly differ from those of the nematodes found in other hosts. the present and ... | 1991 | 1822042 |
| [right heart function and endotoxemia in animals]. | we used a chronic instrumented ovine model to investigate right heart function following an endotoxin bolus. primary aim of the experiments was to elucidate the influence of the right heart on the cardiopulmonary system. furthermore, we tried a thromboxane synthetase inhibitor as a therapeutical approach. at least we investigated the ir-anf release, as the endocrinal function of the right heart, in this model. following the endotoxin administration we observed a massive increase of the pulmonary ... | 1991 | 1833887 |
| activity patterns of primary auditory-nerve fibres in chickens: development of fundamental properties. | we have examined the activity patterns of single auditory-nerve fibers in the chicken and tested for possible changes during post-hatching development. for this purpose, we recorded from fibres in the cochlear ganglion of chickens of two age groups (about p2 and p21) and investigated their spontaneous and sound-evoked activity patterns under nembutal-chloralhydrate anaesthesia. the spontaneous activity of primary auditory neurones was irregular, the average rates were between 20.5 (p2) and 23 (p ... | 1991 | 1774201 |
| starling forces and lymphatic drainage in pleural liquid and protein exchanges. | pleural liquid volume and protein concentration (c) were determined in rabbits 60 min after a 2 ml hydrothorax with various albumin concentrations in ringer, homologous serum or plasma. the absorption rate of the hydrothorax decreased with the increase in colloid osmotic pressure of the pleural liquid (pi), being 0.56 +/- 0.03, 0.32 +/- 0.02 and 0.17 +/- 0.05 ml/h with ringer, 1.1 and 3 g% albumin, respectively, and nil with 5% albumin, serum or plasma. c increased with ringer and 1.1% albumin, ... | 1991 | 1780605 |
| lymph flow transients following elevation of venous pressure in the dog hindpaw. | lymph flow transients were studied in a dog paw preparation when venous pressure was elevated by 15 and 25 mmhg. the lymph flow transients showed a very rapid initial increase which then declined to a steady-state value that was one-half the peak lymph flow response for both pressure changes. lymph flow increased in the initial 5.3 minutes following venous pressure elevation to 10.4 +/- 2.0 and 18.1 +/- 4.5 times the normal lymph flow (mean +/- standard deviation) for the 15 and 25 mmhg increase ... | 1991 | 1791726 |
| in vitro assessment of cardiac performance after irradiation using an isolated working rat heart preparation. | the effect of irradiation on cardiac function was assessed using an isolated working rat heart preparation. the animals were given single doses of x-rays in the range 15-30 gy to their hearts. cardiac output (co = aortic flow + coronary flow), heart weight and body weight were followed for a period of 10 months after treatment. irradiation led to a decrease in cardiac function. this reduction was dose-dependent and progressive with time after treatment. the shape of the frank-starling curves con ... | 1991 | 1674271 |
| comparative studies of the covalent binding of [14c]-2-chloro-4-acetotoluidide by liver and kidney slices of the starling. | in tissue slices of female starlings, binding of [14c]-2-chloro-4-acetotoluidide (cat) radioactivity to liver proteins was almost five times greater than binding to kidney proteins after 2 h of incubation. binding to protein of liver slices increased in a log linear fashion with increasing cat concentrations. binding to protein of kidney slices also increased with increasing concentrations but not in a log linear fashion. mixed-function oxidase inhibitors, skf 525-a and alpha-naphthoflavone, dec ... | 1991 | 1918797 |
| responses of slowly and rapidly adapting receptors in the airways of rabbits to changes in the starling forces. | 1. the responses of the rapidly adapting receptors (rars) and the slowly adapting receptors (sars) of the airways to changes in the starling forces regulating fluid exchange in the pulmonary extravascular space were investigated in anaesthetized rabbits. the hydrostatic pressure in the pulmonary microvasculature was raised by partial obstruction of the mitral valve (mean left atrial pressure increased by approximately 5 and 10 mmhg above the control values) and the concentration of plasma protei ... | 1991 | 1886073 |
| in utero ventilation augments the left ventricular response to isoproterenol and volume loading in fetal sheep. | in its normal circulatory environment, the fetal left ventricle can maximally increase output less than 2-fold, in contrast to the nearly 3-fold increase that occurs at birth. several studies have attributed this finding to fetal myocardial "immaturity," and speculated that there is a rapid maturation of the myocardium in the perinatal period. we investigated the importance of the circulatory environment itself, rather than myocardial immaturity, by measuring left ventricular output (lvo) during ... | 1991 | 1896250 |
| cardiac myosin heavy chain mrna expression and myocardial function in the mouse heart. | the vertebrate heart contains two myosin heavy chain isoforms, alpha and beta, which are differentially expressed. to establish a murine model for gene-targeting experiments, we defined the precise temporal expression of the myosin isoforms during cardiogenesis and obtained quantitative measurements of cardiac performance. the relative levels of the alpha- and beta-cardiac transcripts were determined by isolating the rna from the hearts of cd-1 mice during development and hybridizing the prepara ... | 1991 | 2036722 |
| studies of myocardial protection in the immature heart. v. safety of prolonged aortic clamping with hypocalcemic glutamate/aspartate blood cardioplegia. | this study tests the hypothesis that multidose, hypocalcemic aspartate/glutamate-enriched blood cardioplegia provides safe and effective protection during prolonged aortic clamping of immature hearts. of 17 puppies (6 to 8 weeks of age, 3 to 5 kg) placed on vented cardiopulmonary bypass, five were subjected to 60 minutes of 37 degrees c global ischemia without cardioplegic protection and seven underwent 120 minutes of aortic clamping with 4 degrees c multidose aspartate/glutamate-enriched blood ... | 1991 | 1986168 |
| regional blood flow to canine parietal pleura and internal intercostal muscle. | transcapillary starling forces in the parietal pleura and the underlying interstitium may potentially contribute to the exchange of fluid across this barrier. however, the extent of blood flow to the parietal pleura has not been measured. thus, using standard microsphere techniques, we compared blood flow to the parietal pleura, including the subpleural interstitium, with blood flow to the adjacent internal intercostal muscle, as well as with flows to other serous tissues, including mediastinal ... | 1991 | 2010416 |