| a nervous mechanism for descending inhibition in guinea-pig small intestine. | 1. intracellular recordings were made from neurones in the myenteric plexus of guinea-pig small intestine under conditions in which these neurones received synaptic input from an adjacent segment of intestine.2. most long synaptic pathways in the myenteric plexus were found to lead in an anal direction.3. such pathways could be excited by either distension or transmural electrical stimulation of the intestinal segment.4. similar stimuli evoked inhibitory junction potentials in the circular muscl ... | 1974 | 4838801 |
| a role for the starling (nonlinear) resistorlike action of renal proximal tubules. | | 1972 | 5007014 |
| the cardiorespiratory impairment in cirrhosis and sepsis. an experimental interpretation using octopamine infusion. | the effects of octopamine on systemic and pulmonary circulation and on respiratory parameters have been studied in ten o2 100% breathing pigs. a rise in cardiac index (ci) due to an increase in the dynamics of the left ventricle and a progressive hypoxemia, notwithstanding the hyperventilation, was found. the decrease in arterial o2 tension was due to a rise in the pulmonary shunt fraction (qs/qt). the statistical analysis of cardiorespiratory parameters demonstrated that the high flow state lin ... | 1983 | 6403256 |
| role of peritubule starling forces in proximal reabsorption following albumin infusion. | | 1972 | 5075149 |
| [frequency potentiation and frank-starling mechanism in canine ventricle under sinus node rhythm and ventricular pacing]. | | 1971 | 5099687 |
| the role of inotropic variation in ventricular function during atrial fibrillation. | a series of experiments were performed upon intact anesthetized dogs to determine the relevance of a variety of hemodynamic variables to the irregular ventricular performance associated with atrial fibrillation. during experimentally induced atrial fibrillation central aortic pulse pressure was measured in relation to the duration of the preceding diastolic interval, the relative degree of cycle-length change, the magnitude of the preceding aortic end-diastolic pressure, the rate of ventricular ... | 1970 | 5443174 |
| coronary blood flow, oxygen delivery rate and cardiac performance. | 1. studies have been made on the isolated blood-perfused heart of dogs in which isometric tension development at various settings of resting tension (rt) was measured at various levels of o(2) delivery rates controlled by altering (a) coronary blood flow (cbf), (b) o(2) capacity or (c) o(2) saturation of the perfusate. measurements were also made of o(2) consumption and vascular perfusion resistance.2. the capacity of the left ventricle to develop tension at any given setting of resting tension ... | 1971 | 5558342 |
| [setting up and survival of the starling rat heart-lung preparation]. | | 1967 | 5613026 |
| critical closure of pulmonary vessels analyzed in terms of starling resistor model. | | 1968 | 5647639 |
| [the action of various substances on the function of the starling rat heart-lung preparation]. | | 1968 | 5709779 |
| relationships between intestinal absorption and hemodynamics. | there are many interactions between intestinal blood flow and absorption. these include the support of transcellular transport by o2 delivery; the passive effects of starling forces on absorption, secretion, and mucosal conductance; the washout of absorbed materials; and countercurrent exchange. blood flow hemodynamics, and absorption interact. regulatory mechanisms add a tertiary influence to these interactions. further progress in this area would be greatly helped by techniques that could meas ... | 1982 | 6122423 |
| erythrocytic phosphates and flying activity in birds. | 1. the intraerythrocitary organic phosphates in different avian species (sturnus vulgaris, apus apus, gallus gallus domesticus, coturnix coturnix japonica and columba livia) were analyzed by ionic exchange chromatography. the chromatograms of these species revealed the presence of adp, atp, gtp, ipp and inorganic phosphate. 2. the main organic phosphates (atp and ipp) and the inorganic phosphate were also evaluated, directly, in other specimens. the ipp levels were very similar in all species; h ... | 1983 | 6132731 |
| protection of ischemic rabbit myocardium by glutamic acid. | glutamic acid may protect the ischemic myocardium by increasing the flux through anaerobic pathways for atp production. we tested this in isolated rabbit hearts that were treated with 0 or 2 mm glutamate. hearts were stabilized for 30 min, subjected to ischemia for 30 min, and then reperfused for 30 min. cardiac performance was defined by measuring peak left ventricular pressure (plvdp) at the apex of a starling curve and expressed as the %plvdp attained during the preischemia period. glutamate ... | 1983 | 6137148 |
| vertebrate host specificity and experimental vectors of plasmodium (novyella) kempi sp. n. from the eastern wild turkey in iowa. | vertebrate host specificity, experimental laboratory vectors, and a description of plasmodium (novyella) kempi sp. n. from eastern wild turkeys (meleagris gallopavo silvestris vieillot) in iowa are presented. plasmodium kempi is infective for domestic turkeys, bobwhites (colinus virginianus), chukars (alectoris graeca), guinea fowl (numida meleagris), peacocks (pavo cristatus), and canaries (serinus canaria), produces a transient infection in mallards (anas platyrhynchos) and domestic geese (ans ... | 1983 | 6644918 |
| [effect of preliminary blockade of alpha- and beta-adrenoreceptors on stress-induced disorders of myocardial relaxation and contractile functions]. | effect of preliminary administration of the alpha-adrenoblocker phentolamine and the beta-adrenoblocker inderal on stress-induced disturbances of myocardial extensibility, contractile function and myocardial resistance to hypoxia and excess ca2+ was studied on an isometrically contracting isolated right atrium of the rat. inderal substantially prevented the post-stress decrease in atrial extensibility and almost completely prevented the stress-induced decline in the developed tension and the fra ... | 1983 | 6140967 |
| effects of arteriolar vasodilators on hepatic venous compliance and cardiac output in anesthetized cats. | the effects of cumulative doses of seven arteriolar vasodilators were examined in cats anesthetized with pentobarbital. cardiac output was measured by a thermodilution technique and hepatic venous compliance by plethysmography. all the drugs produced dose-related decreases in total peripheral resistance. diazoxide, prazosin, and sodium nitroprusside produced no significant changes in hepatic venous compliance or cardiac output. diazoxide and prazosin produced no change in right atrial pressure, ... | 1981 | 6173533 |
| vasodilatation by acetylcholine is endothelium-dependent: a study by sonomicrometry in canine femoral artery in vivo. | external diameter of the femoral artery was measured by sonomicrometry in the anaesthetized dog. intra-arterial acetylcholine lowered arterial pressure and thereby passively lowered diameter. when blood flow and distal resistance were controlled by roller pump and starling resistor respectively, acetylcholine (0.1-10 microm) and substance p (0.1-1 nm) both caused up to 10% increase in diameter. removal of endothelium by mechanically rubbing the artery lumen abolished the dilator response to acet ... | 1983 | 6197520 |
| postextrasystolic potentiation during spontaneous ventricular ectopy in man. associated left ventricular volume changes determined by list mode radionuclide ventriculography. | five patients with spontaneously arising frequent ventricular ectopia were studied by list mode radionuclide ventriculography. changes in left ventricular volumes reflected the increased inotropy of the postextrasystolic sinus beats: stroke volume increased by +36.0 +/- 32.8% (p less than 0.05) and end-systolic volumes decreasing by 13.6 +/- 7.3% (p less than 0.02) leading to an increased ejection fraction (+31.1 +/- 23.8%; p less than 0.05). there were no significant increases in end-diastolic ... | 1984 | 6210263 |
| left ventricular hypertrophy improves cardiac performance in spontaneously hypertensive rats. | cardiac function was studied in spontaneously breathing, adult spontaneously hypertensive rats (shr) and wistar-kyoto normotensive rats (wky). by rapid intravenous blood infusion, the relation between left ventricular end-diastolic pressure (lvedp) and stroke infusion, the relation between left ventricular end-diastolic pressure (lvedp) and stroke volume (sv) was determined while the cardiac nervous control was pharmacologically blocked. since sv is greatly influenced by the level of afterload ( ... | 1982 | 6215829 |
| mechanisms of cardiac contraction. what roles for preload, afterload and inotropic state in heart failure? | there is evidence that sarcomere length is maximal and changes little during chronic cardiac enlargement, and that the failing heart does not operate on a true descending limb of the frank-starling curve. however, increases of ventricular end-diastolic volume over time clearly are important at the geometrical level in maintaining stroke volume. when the preload reserve is fully utilized, afterload mismatch can exist in the steady state to produce operation of the heart on an apparent descending ... | 1983 | 6220896 |
| diastolic properties of the hypertrophied left ventricle in spontaneously hypertensive rats. | the influence of myocardial hypertrophy on left ventricular volume compliance was studied in vitro in isolated hearts of 4 and 19 month old spontaneously hypertensive rats (shr) and normotensive wistar-kyoto rats (wky). in both shr groups diastolic volume compliance was similar to that in the controls, despite the presence of left ventricular hypertrophy. this seems to be mainly due to an altered geometric situation, since with increased wall thickness to internal radius ratio (w/ri), which was ... | 1983 | 6226173 |
| activation of contraction in cardiac muscle. | this paper begins with consideration of a qualitative model of excitation-contraction coupling in cardiac muscle which is based to a large extent on experimental work carried out on isolated preparations of cardiac muscle by earl wood during sabbatical years in europe in 1966-67 and 1972-73. it goes on to consider newer evidence about excitation-contraction coupling that has been obtained from studies of "skinned" fiber preparations (that is, muscles in which the cell membranes have been disrupt ... | 1982 | 6289019 |
| modulation of jejunal ion and water absorption by endogenous angiotensin after hemorrhage. | in the pentobarbital sodium-anesthetized rat, hemorrhage of blood equivalent to 1% body weight (18.4% blood volume) increases plasma renin activity and plasma aldosterone concentration and also markedly elevates jejunal ion and water absorption. infusion of angiotensin ii (aii) also stimulates jejunal absorption, and in a manner similar to hemorrhage. the elevation of jejunal absorption in response to hemorrhage is not affected by removal of the adrenals but is totally inhibited by the convertin ... | 1984 | 6372521 |
| haemodynamic changes in insulin-induced hypoglycaemia in normal man. | haemodynamic variables (plasma volume, heart rate, blood pressure, cardiac output, stroke volume, pulmonary tissue volume, total peripheral vascular resistance, hepato-splanchnic vascular resistance, lower extremity vascular resistance and plasma catecholamines) were measured before and after insulin-induced hypoglycaemia in seven healthy men. plasma volume decreased significantly at the nadir of glucose (mean decrease 222 +/- 41 ml) and subsequently increased to pre-hypoglycaemic values within ... | 1984 | 6376241 |
| comparison of the effects of positive end-expiratory pressure and jugular venous compression on canine cerebral venous pressure. | the confluent sinus pressure was measured in eight mongrel dogs in the head-up position to compare the effectiveness of positive end-expiratory pressure (peep) and jugular venous compression in increasing cerebral venous pressure. when the head was elevated 30 cm above the heart, confluent sinus pressure decreased from 9.6 +/- 1.8 (mean +/- sem) to -5.3 +/- 0.5 mmhg. at constant arterial carbon dioxide tension (paco2 = 28 +/- 2 mmhg), peep (20 cmh2o) did not increase cerebral venous pressure. ho ... | 1984 | 6380344 |
| distribution of body fluids: local mechanisms guarding interstitial fluid volume. | the plasma volume is determined by fluid influx through drinking and outflux by renal excretion. both fluxes are regulated according to plasma volume and composition through arterial pressure, osmoreceptors and vascular stretch receptors. as to the remaining part of the extracellular volume, the interstitial space, there is no evidence that its volume (ifv), pressure or composition are sensed in such a way as to influence water intake or excretion. nevertheless, ifv is clearly regulated, often p ... | 1984 | 6399307 |
| mechanism of action of nitrates. role of changes in venous capacitance and in the left ventricular diastolic pressure-volume relation. | nitroglycerin, when administered to patients with heart failure, causes a marked reduction in left ventricular filling pressure but often an increase in stroke volume and stroke work; based on the frank-starling principle, such a reduction in "preload" would be expected to result in a decrease in left ventricular end-diastolic volume and, therefore, a decline in stroke volume. assessment of pressure-volume coordinates, however, has revealed that nitroglycerin produces a downward shift in the pre ... | 1984 | 6430073 |
| intestinal filtration as a consequence of increased mucosal hydraulic permeability. a new concept for laxative action. | two mechanisms have been proposed to explain the secretory action of laxative compounds in the intestine: 1. increase of the intracellular amount of cyclic adenosine monophosphate due to stimulation of the adenylate cyclase system and 2. inhibition of intestinal transfer processes, in particular the na,k-atpase activated sodium absorption. in a set of in vivo and in vitro experiments in rat colon it could be demonstrated that dihydroxy bile acids (deoxycholate) and diphenolic laxatives (oxypheni ... | 1980 | 6445443 |
| left ventricular adaptation to volume overload from large aortocaval fistula. | the manner in which the left ventricle responds to an acute volume overload has not been well defined. left ventricular performance was studied in six chronically instrumented resting awake dogs in the control state and serially after creation of a large abdominal aortocaval shunt. ultrasonic transducers measured minor and major axis diameters and equatorial wall thickness. left ventricular pressure was obtained with micromanometers. cardiac contractility was evaluated by the load-independent co ... | 1984 | 6463865 |
| sympathetic stimulation and intestinal capillary fluid exchange. | sympathetic nerve stimulation is generally considered not to alter intestinal capillary pressure or filtration rate because of appropriate adjustments in the pre-to-postcapillary resistance ratio. to directly assess this possibility, we measured lymph flow, capillary pressure, capillary filtration coefficient, and the transcapillary oncotic pressure gradient in the cat small intestine. measurements were taken under control conditions and during the steady-state phase of periarterial nerve stimul ... | 1984 | 6476118 |
| comparison of heart function in male and female rats. | the objective of this investigation was to compare intrinsic cardiac function in male and female rats. the first series of experiments (series i) compared hearts from age-matched males and females at 18 weeks of age. since body and heart weight were 65 and 51 per cent greater respectively in male rats in this study, a second series of experiments was performed (series ii) where heart mass was matched in males and females by studying males at 10 weeks of age and females at 18 weeks of age. cardia ... | 1984 | 6487233 |
| tubuloglomerular feedback and interstitial pressure in obstructive nephropathy. | the possible role of the tubuloglomerular feedback (tgf) mechanism in the altered glomerular hemodynamics and tubular reabsorption which occur with prolonged (24-hr) ureteral obstruction and the changes in renal interstitial hydrostatic and oncotic pressure which may modulate tgf sensitivity were examined. the proximal tubule stop-flow pressure (psf) response to increased distal tubular flow rates (tgf activity) was determined in rats with sham operation, 24-hr unilateral ureteral obstruction (u ... | 1984 | 6513275 |
| role of solute in the early restitution of blood volume after hemorrhage. | we examined the putative roles of decreased capillary pressure and increased transcapillary osmolar gradient in mediation of the early restitution of blood volume after hemorrhage by comparing the degree of restitution of plasma volume and protein and comparing changes in capillary pressure and osmolality in awake dogs with those in dogs anesthetized with pentobarbital. decreases in estimated capillary pressure and increases in plasma osmolality were greater in anesthetized than in awake dogs. h ... | 1983 | 6612579 |
| toxicokinetics, covalent binding and histopathological features of [14c]2-chloro-4-acetotoluidide toxicity in the starling after intravenous administration. | the toxicokinetics and subcellular covalent binding of the avicide 2-chloro-4-acetotoluidide (cat) were examined in the starling. intravenous administration of 4.5 mg/kg ring-labeled [14c]-cat produced biphasic decay curves of the radioactivity in plasma and other tissues. the alpha phase of the decay curves ranged from 17 min to 1 hr while the beta phase of the decay curves varied widely from 4 hr up to 23 hr. significant amounts of tissue covalent binding were found only in the plasma, liver, ... | 1983 | 6617827 |
| modification of lymph by lymph nodes. ii. effect of increased lymph node venous blood pressure. | a previous study from this laboratory demonstrated that lymph nodes can change the protein concentration and colloid osmotic pressure of lymph by transfer of protein-free fluid between the blood and lymph compartments. in that study a starling force disequilibrium across the blood-lymph barrier caused fluid to transfer through the barrier in the direction required to establish equilibrium of starling forces. in the present study we examined the effect of increased lymph node venous blood pressur ... | 1983 | 6624930 |
| pulmonary hemodynamics and gas exchange properties during progressive edema. | in this investigation we have studied the effect of increments of pulmonary edema on pulmonary hemodynamics, and physiological and hemodynamic shunt in an isolated lung preparation. hemodynamic shunt was defined by the slope of the relationship between pulmonary arterial and airway pressures; when the slope decreases, there is a greater degree of shunt. cardiovascular changes were analyzed using a starling resistor model of the pulmonary circulation where the effective downstream pressure to flo ... | 1983 | 6629947 |
| effector loci for renal nerve control of cortical microcirculation. | to determine the effector loci for renal neural vasomotor control, we performed micropuncture measurements before or after renal nerve stimulation and during low- (0.5-1.5 hz) (lfs) or high- (3-5 hz) (hfs) frequency nerve stimulation in munich-wistar rats. in response to hfs, single nephron glomerular filtration rate decreased on average from 24.1 +/- 4.1 to 10.4 +/- 2.3 nl/min. although mean glomerular transcapillary hydraulic pressure difference remained essentially constant, hfs led to a mark ... | 1983 | 6638175 |
| effect of inspiration on inferior vena caval blood flow in dogs. | inferior vena cava flow of anesthetized open-chest dogs was drained to a reservoir from a cannula above the diaphragm and returned to the atrium at constant rate. at selected base-line caval pressures, the caval flow and pressures in the abdomen (pab), iliac vein (piv), and downstream cavae (pvc) were recorded during spontaneous breathing, cyclic phrenic nerve stimulation, and cyclic lowering of caval drain pressure. each augmented flow unless pab exceeded pvc by at least ca. 5 cmh2o. in other d ... | 1983 | 6662760 |
| oxychlordane, hcs-3260, and nonachlor in birds: lethal residues and loss rates. | oxychlordane reached lethal levels in birds given dietary dosages of hcs-3260 (70.75% cis-chlordane and 23.51% trans-chlordane) at 6 levels from 50 to 500 ppm. oxychlordane ranged from 9.4 to 22.1 ppm in brains of cowbirds (molothrus ater), grackles (quiscalus quiscula), and red-winged blackbirds (agelaius phoeniceus) that died on dosage and from 1.3 to 4.8 ppm in sacrificed birds, providing a clear diagnostic separation. among starlings (sturnus vulgaris), however, oxychlordane ranged from 5.0 ... | 1983 | 6668611 |
| stress damage to nonischemic divisions of the heart in experimental infarction and its prevention. | recently, it has been shown that nonischemic parts of the heart in myocardial infarction were separated from ischemic damaged ones by a sharp border zone. in this connection, the disturbance of contractile function of the myocardium of nonischemic parts is suggested to result from the infarction-concomitant emotional-painful stress. in order to test this assumption, the contractile function of the right auricle, which is an a priori nonischemic heart division, was studied in rats subjected to my ... | 1983 | 6682360 |
| compensatory cardiac mechanisms evoked by acute occlusion of the right coronary artery in dogs. | the cardiac response to intermittent occlusion of the right coronary artery was examined in anesthetized open-chest dogs at different levels of blood volume. the reduction in stroke volume averaged 15 +/- 2% and was related to the extent of the ischemic area (r = 0.72), which comprised 45-70% of the free wall of the right ventricle. ultrasonic recordings of segment lengths showed end-diastolic distention and activation of the frank-starling mechanism in the uninjured parts of the free wall. the ... | 1984 | 6711336 |
| modified starling heart-lung preparation for measuring coronary vascular resistance. | a simplified in situ heart-lung preparation has been developed for measuring coronary vascular resistance and left ventricular performance. it provides the ability to observe the direct, cardiac effects of an agent independent of the central nervous system and circulating hormones. it eliminates the need for cross-matched blood or the use of colloidal solutions and permits direct control of coronary driving pressure and heart rate, and partial control of myocardial compression. the preparation s ... | 1984 | 6713600 |
| [hemoglobins of thecommon starling (sturnus vulgaris, passeriformes). the primary structures of the alphaa, alphad and beta chains]. | the primary structures of the major hemoglobin component hba (alpha a- and beta-chains) and the minor component hbd (alpha d-chains, beta-chains are identical with those of hba) of the starling (sturnus vulgaris) are given. the order passeriformes, to which this species belongs, represents 5/8 of all species of birds. comparing starling and greylag goose (anser anser) hemoglobins, hba alpha a-chains differ by 20 amino acids or 23 nucleotides (3 two point mutations), beta-chains by 14 amino-acid ... | 1984 | 6714943 |
| depressed function of isolated hearts from hyperdynamic septic rats. | the aim of this study was to determine if hearts removed from rats in sustained hypermetabolic sepsis possessed normal physiological reserves as defined by frank-starling curves. the resting cardiac output of these hearts is elevated in vivo and this is mediated by an increased heart rate. in this study mechanical function was assessed under in vitro conditions in which preload could be varied and controlled. isolated perfused working hearts from septic animals showed depressed cardiac performan ... | 1984 | 6722992 |
| comparative features of starling-lymphatic interaction at the pleural level in mammals. | pleural liquid pressure was measured with saline-filled cannulas in rats, rabbits, cats, pups (4-5 days and 2 mo), small and large dogs, and pigs. on both the costal and mediastinal sides pleural liquid pressure at a level corresponding to the tricuspid valve decreased with increasing body mass; because this behavior was more marked on the mediastinal than on the costal side, a horizontal costomediastinal pleural liquid pressure gradient developed. no differences in liquid pressure were found in ... | 1984 | 6725079 |
| the influence of blood pressure on trans-synovial flow in the rabbit. | fluid exchange across the synovium lining the cavity of extended knees was studied in twenty rabbit hindquarters. the isolated hindquarters were perfused with blood from an extracorporeal pump-oxygenator system at controlled arterial pressure (pa) and venous pressure (pv). intra-articular pressure (pj) was set at 18 cmh2o in most experiments. the rate of trans-synovial absorption of krebs solution (qs), measured by a drop-counter, was a negative linear function of pa (70-160 mmhg) and of pv (2-4 ... | 1984 | 6737295 |
| verapamil cardioplegia: improved myocardial preservation during global ischemia. | to determine whether the calcium antagonist verapamil can produce satisfactory myocardial preservation during global ischemia, we studied three groups of eight dogs. serial left ventricular biopsy specimens were taken for adenosine triphosphate and creatine phosphate content. arterial and coronary sinus blood samples were obtained for lactate and oxygen content determination prior to ischemia, immediately after the ischemic interval, and after a 30 minute reperfusion period. starling and isovolu ... | 1984 | 6738103 |
| physiological characteristics of diameter pulses in the fetal descending aorta. | a study was performed to establish the dynamic behavior in situ of the descending aorta in the human fetus. the pulsatile movements of the vessel walls were recorded in 36 clinically normal fetuses using a real-time phase-locked ultrasonic system measuring echo movements with high spatial and temporal resolution. the mean amplitude of the diameter pulsations was similar in the 28th - 35th week to that in the 36th - 40th week but, as the apparent diastolic diameter increased, the pulse-elicited i ... | 1984 | 6741461 |
| modulation of jejunal ion and water absorption by endogenous angiotensin after dehydration. | in the pentobarbital sodium-anesthetized rat, dehydration for 24 h increased ion and water absorption from the jejunum. dehydration also elevated plasma concentrations of angiotensin peptides and plasma renin activity but did not significantly alter plasma aldosterone concentrations. infusion of tyramine, norepinephrine, and angiotensin ii (aii) also stimulated jejunal absorption in a manner similar to dehydration. the elevation of jejunal absorption in response to dehydration is totally inhibit ... | 1984 | 6742121 |
| effects of bradykinin on renal interstitial pressures and proximal tubule reabsorption. | renal interstitial starling forces have been postulated as the link between the peritubular microcirculation and fluid reabsorption by the proximal tubule. the renal vasodilator bradykinin was used as a tool to test this relationship in micropuncture studies in the rat. bradykinin increased peritubular capillary and interstitial hydrostatic pressures and decreased peritubular and interstitial oncotic pressures. the balance of starling forces in the interstitium (interstitial oncotic pressure min ... | 1984 | 6742206 |
| blood flow measurements in the fetal descending aorta: technique and clinics. | a combination of two-dimensional and realtime pulsed-doppler ultrasound provides a noninvasive method of measuring human fetal blood flow without side effects. by not altering the physiological conditions of the fetus, it minimizes external stimuli that might affect blood flow. however, due to the inaccessibility of the vessels under investigation, errors from the ultrasound technique arise and these are still being assessed. studies of fetal blood flow suggest that the fetal circulation has a l ... | 1984 | 6744689 |
| the absence of the descending limb of the frank-starling curve of the depressed guinea pig whole ventricle. | to determine whether the descending limb of the frank-starling curve can be detected in the whole ventricle when contractile state is impaired, volume-active pressure relationships were investigated in deteriorated preparations of isolated guinea pig hearts. the pressure developed by the isovolumic left ventricle as well as the first derivative of the pressure were determined during progressive dilation of the left ventricle up to a resting pressure of 60 mmhg. coronary flow was provided by a co ... | 1984 | 6518336 |
| effect of lung inflation on pulmonary vascular resistance by arterial and venous occlusion. | to explain the changes in pulmonary vascular resistance (pvr) with positive- and negative-pressure inflation (ppi and npi, respectively), we studied their effects in isolated canine left lower lobes perfused at constant flow rate. the venous pressure was kept constant relative to atmospheric pressure during lung inflation. the total arteriovenous pressure drop (delta pt) was partitioned with the arterial and venous occlusion technique into pressure drops across arterial and venous segments (larg ... | 1982 | 6757207 |
| a starling resistor regulates cerebral venous outflow in dogs. | this investigation was undertaken to determine whether a starling resistor or venous waterfall effect exists between the sagittal sinus and the cerebral veins such that increases in sagittal sinus pressure (pss) do not abolish cerebral venous outflow and to examine two possible contributions of extracranial venous valves in regulating outflow. anesthetized dogs were subjected to positive end-expiratory pressure (peep) before and after intracranial pressure (pic) was elevated by inflation of an e ... | 1982 | 6759493 |
| correlation of fluid exchange in the microcirculation and macrocirculation. | accurate, quantitative information relating to hydraulic conductivity (lp) of the capillary wall in any organ of tissue is essential as the first step toward understanding fluid homeostasis. any perturbation which permanently alters fluid balance will ultimately lead to death and destruction of tissues in the living organism. this report summarizes some recent information relating to lp measurements in single capillary and whole organ experiments. it is shown that the single capillary and whole ... | 1982 | 6765283 |
| transvascular fluid balance in the lung. | 1. the transvascular fluid balance has been studied in isolated blood-perfused lungs of rabbit and cat. during periods of left atrial pressure (lap) elevation, changes in preparation weight were measured. in some experiments simultaneous recordings of changes in blood volume, as judged by changes in emitted radioactivity from (51)cr labelled red blood cells, were performed.2. in nine out of eleven experiments, elevation of lap by 5 mm hg within a test period of 8 min resulted in new weight stabi ... | 1969 | 5355000 |
| the direct myocardial energetic response to nitroglycerin in the rabbit heart. | the coronary resistance, total heat production, oxygen consumption and isovolumic mechanical performance were measured simultaneously in the isolated beating rabbit heart. the direct effects of nitroglycerin (0.12 mg/l) were determined. the expected coronary dilatation occurred; coronary resistance fell by 21.5% independent of mechanical performance. there was a 14% fall in mechanical performance at the apex of the frank-starling curve and lesser reductions at less-than-apical diastolic volumes. ... | 1981 | 6785417 |
| dynamics of the interventricular septum and free ventricular walls during selective left ventricular volume loading in dogs. | a previous study suggests that a change in the position of the interventricular septum played an important role in regulating cardiac performance during selective right ventricular volume loading. in the present study the cardiac response to selective left ventricular volume loading induced by a shunt between the subclavian artery and the left atrium was examined in anesthetized open-chest dogs. opening the shunt increased left and reduced right ventricular stroke volume, particularly after bloo ... | 1983 | 6650208 |
| mechanical interaction between the ventricles. | we investigated ventricular interaction by the use of six excised, perfused, canine hearts. in this preparation, we could change the filling pressure of the right and left ventricles independently, thereby breaking the normal series-pump arrangement. we found that mechanical ventricular interaction exists in diastole and in systole. namely, not only decreased diastolic ventricular compliance, but also the reduced performance in either ventricle was found, when the opposite ventricular pressure w ... | 1983 | 6651741 |
| mechanism of the renal response to contrast medium in dogs. decrease in renal function due to hypertonicity. | radiographic contrast media (cm) (meglumine/sodium diatrizoate-76%; 1650 mosm/kg) and other hypertonic solutions induce renal vasoconstriction by an unknown mechanism. in anesthetized dogs, renal blood flow (rbf) was measured with an electromagnetic flowmeter and filtration fraction (ff) and glomerular filtration rate (gfr) by the renal extraction of technetium-99m tin chelate. ureteral pressure (up) and wedged renal venous pressure (vp) were measured as indices of intrarenal pressure. measureme ... | 1983 | 6832934 |
| influence of the velocity of changes in end-diastolic volume on the starling mechanism of isolated left ventricles. | 1. in this study the relationships between active developed systolic pressure, end-diastolic pressure and different diastolic volumes are studied in tyrode perfused isolated rabbit left ventricles. contractions were isovolumic. 2. rapid diastolic volume changes were imposed on top of different preset basic diastolic volumes. these volume changes are shown to produce systolic and diastolic pressure values that cannot be explained by assuming a single pressure-volume relation during systole and di ... | 1983 | 6844128 |
| the short-term effects of increasing plasma colloid osmotic pressure in patients with noncardiac pulmonary edema. | we infused hyperoncotic albumin (25 or 50 gm of a 50% solution) into patients with noncardiac pulmonary edema (adult respiratory distress syndrome [ards]) to evaluate its effect on the transmicrovascular flux from blood to pulmonary edema fluid of two radiotracers--111in-dtpa (mol wt 504) and 125i-human serum albumin (hsa) (mol wt 69,000). two groups of patients were studied--one with a modest increase in permeability of the pulmonary alveolocapillary membrane to 125i-hsa (group 1) and another w ... | 1983 | 6845168 |
| the effect of thyroidectomy on testicular size and on the photorefractory period in the starling (sturnus vulgaris l.). | | 1972 | 5016291 |
| the optimal temperature for preservation of the myocardium during global ischemia. | to determine the myocardial temperature that provides maximal preservation of the heart during global ischemic arrest, five groups of dogs were studied (6 per group). in all animals, the aorta was cross-clamped for 120 minutes. serial biopsies were done for determination of adenosine triphosphate and creatine phosphate, and study by electron microscopy. starling curves were derived prior to cardiopulmonary bypass and 60 minutes after bypass. mitochondrial changes were graded on a scale of 0 to 4 ... | 1983 | 6860004 |
| reabsorption of a saline- or plasma-induced hydrothorax. | in supine rabbits injection of 2 ml of saline into the lower right diaphragmatic region increased pleural liquid pressure at the injection point and, to a minor extent, on the costal and mediastinal side, indicating a redistribution of liquid among the pleural compartments. over a period of 120 min end-expiratory liquid pressure on the diaphragmatic and costal surfaces approached the control value as a result of local reabsorption. no difference in the time course of liquid pressure was found on ... | 1983 | 6874479 |
| effects of secretin on peritubular capillary physical factors and proximal fluid reabsorption in the rat. | the effects of secretin vasodilation on peritubular capillary starling forces and absolute proximal reabsorption were examined in the rat. secretin was infused at 75 mu/kg per min into the aorta above the left renal artery. efferent plasma flow increased from 125 +/- 28 to 230 +/- 40 nl/min with secretin infusion. single nephron filtration rate (44 +/- 6 vs. 44 +/- 7 nl/min) and absolute proximal reabsorption (21 +/- 5 vs. 21 +/- 4 nl/min) were not significantly changed. peritubular capillary an ... | 1983 | 6874958 |
| bayliss-starling memorial lecture (1982). induction of sleep by muramyl peptides. | | 1983 | 6875901 |
| micropuncture study of urate transport by superficial nephrons in avian (sturnus vulgaris) kidney. | tubule fluid samples from proximal tubules of superficial, reptilian-type nephrons of the european starling (sturnus vulgaris) were obtained by micropuncture and, along with plasma samples, were analyzed for urate by high performance liquid chromatography with electrochemical detection, as well as for the elements sodium, chloride, calcium, magnesium, phosphorus and potassium by electron microprobe analysis. all proximal tubules sampled showed net secretion of urate, but the magnitude of transpo ... | 1983 | 6878012 |
| intratubular and peritubular capillary hydrostatic and oncotic pressures after chronic renal sympathectomy in the anaesthetized rat. | the possible role of peritubular capillary physical forces in the diuretic-natriuretic effects of chronic renal denervation was investigated in inactin-anaesthetized nondiuretic control (c) and unilaterally denervated (d) rats. micropuncture techniques were combined with measurement of intratubular and peritubular capillary hydrostatic pressures and afferent and efferent arteriolar plasma oncotic pressures were determined, as well. compared to data of c rats and of innervated kidneys, marked den ... | 1983 | 6889106 |
| body fluid homeostasis in man. a contemporary overview. | in the steady state, urinary excretion of sodium is closely matched to dietary salt intake. given rigorous defense of extracellular fluid osmolality, it is the quantity of sodium in the extracellular fluid that determines the volume of this compartment. changes in extracellular fluid volume are detected by volume sensors located in the intrathoracic vascular bed, kidney and other organs. these mechanoreceptors gauge the adequacy of intravascular volume, relative to capacitance, at various sites ... | 1981 | 7006395 |
| artificial ventilation with peep; the influence on cardiac output in the simulated normo-, hypo- and hypervolemic state. | observations of the influence of artificial ventilation with peep on cardiac output are unequivocal. not only the measure of the end-expiratory pressure and lung compliance play a role, but also the circulating blood volume. in healthy laboratory animals a state of normo-, hypo- and hypervolemia was simulated by changes in position in neurolept-anesthesia. in all cases artificial ventilation with peep induced a decrease of cardiac output as a consequence of a decrease of stroke volume. these res ... | 1981 | 7015171 |
| pulmonary microvascular clearance of radiotracers in human cardiac and noncardiac pulmonary edema. | we examined the integrity of the alveolocapillary membrane in human cardiac (hydrostatic) (group 1) and noncardiac (permeability) (group 2) edema by measuring the clearance of two intravenously administered radiotracers from the blood to suctioned bronchoalveolar secretions (bas), representing pulmonary edema fluid, and compared the clearances to simultaneously measured pulmonary capillary wedge pressure (pcwp) and colloid osmotic pressure (cop), representing the intravascular starling forces, p ... | 1981 | 7021502 |
| [afterload reduction and vasodilator therapy (author's transl)]. | the concept of clinical application of the vasodilator therapy for the treatment of cardiac failure is based on the experimental findings that defined the inverse relationship between force and velocity or extent of muscle shortening at constant muscle lengths. in the intact heart, a new construct has recently been proposed in hopes of better understanding the behavior of the normal or depressed human ventricle in which the shortening during ejection is considered to reflect the appropriateness ... | 1981 | 7035310 |
| [cellular mechanisms of the frank-starling phenomenon]. | | 1982 | 7039169 |
| prostaglandin mediation of unstable hemodynamics during lung perfusion. | positive end-expiratory pressure (peep) leads to a fall in both mean arterial blood pressure (map) and cardiac output (co). this study tests the hypothesis that humoral factors, particularly prostanoids, are important mediators of these events. a support dog was used for ex vivo perfusion of an isolated left lung lobe (lll) at a fixed flow. in group i (n = 10) an isolated, isovolumetrically contracting dog heart was placed in circuit between the support dog and lll. indomethacin (5 mg/kg) was us ... | 1982 | 7046122 |
| [left ventricular function. study during artificial ventilation with peep in the dog (author's transl)]. | according to powers et collaborators the hypothesis that intramyocardial vessels may be collapsed in artificially ventilated patient with added peep, could be arisen. so, myocardial ischemia may explain why in some of those ones there appear signs of left ventricular failure. to test whether this reasoning was correct we measured lvedp in normal dogs submitted to increasing levels of peep up to 40 cm h2o. our results seem to point towards the following conclusions: a) in normal dogs, starling re ... | 1981 | 7051900 |
| proximal reabsorption during metabolic acidosis in the rat. | the mechanism by which proximal volume reabsorption is reduced during hyperchloremic metabolic acidosis was studied using free-flow micropuncture techniques in munich-wistar rats. compared with control hydropenic conditions, absolute rates of proximal total co2 and water reabsorption rates during nh4cl-induced metabolic acidosis were diminished: from 557 +/- 35 to 204 +/- 19 pmol/min and from 13.0 +/- 1.0 to 9.7 +/- 0.6 nl/min, respectively. inhibition of proximal volume reabsorption during meta ... | 1982 | 6805335 |
| role of venoconstriction in the cardiovascular responses of ducks to head immersion. | central venous pressure of ducks rose from resting values of 0.31 +/- 0.16 (se) to 1.75 +/- 0.20 kpa during forced head immersion. because a similar increase in mean circulatory pressure (pmc) was also observed (0.71 +/- 0.16 to 2.15 +/- 0.20 kpa) the rise in central venous pressure was attributed to a venoconstrictor mechanism. when this venoconstrictor-induced rise in central venous pressure was prevented by graded withdrawal of venous blood, then immersion bradycardia was inhibited, and the r ... | 1983 | 6824107 |
| influence of atrial systole on the frank-starling relation and the end-diastolic pressure-diameter relation of the left ventricle. | the influence of atrial systole on the left ventricular function curve (stroke volume vs end-diastolic pressure or end-diastolic diameter) and on the left ventricular end-diastolic pressure diameter relation was studied in nine anesthetized, open-chest dogs whose atrioventricular (av) node had been completely blocked. measurements were made during volume loading with the pericardium closed and opened and during alternate av sequential pacing (to permit atrial contribution to ventricular filling) ... | 1983 | 6831669 |
| the effect of deoxycorticosterone on the interstitial fluid pressure in normal rats. | interstitial fluid pressure was measured by guyton's capsular method in the subcutaneous tissue of rats after a single doc i.p. injection. regardless of the dose of doc, the pressure-time curve showed three phases: latency, decrease and recovery. the maximum drop in pressure and the recovery time were dose-dependent. maximum decrease in interstitial fluid pressure after 0.25; 0.50; 0.75; 1.00 mg/100 g body wt of doc was 3.2; 7.1; 9.2 and 10.6 mmhg, respectively. it was found that the recorded pr ... | 1982 | 7168345 |
| the morphology of the starling (sturnus vulgaris) bursa of fabricius: a scanning and light microscope study. | two starlings, a male and female, were sampled from the nest in 1980 and 1981. scanning electron microscopy and light microscopy revealed the bursa of fabricius to be similar in these two nestlings. in the center of the elongated bursa is a wide central canal from which blind secondary canals branch. the luminal surface of the central canal is smooth and lacks the plicae characteristically observed in the chicken's bursa. the central and secondary canals contain a mixture of epithelial cells: mu ... | 1982 | 7181139 |
| [cardiac contraction. ii. physiological basis of the frank-starling mechanism]. | | 1982 | 7186387 |
| preload changes modify systolic pressure-diameter relations in the conscious dog. | the behavior of the end-systolic ventricular diameter was examined during control state, atrial pacing, and acute volume loading (vl) followed by methoxamine infusion in conscious dogs instrumented with a left ventricular micromanometer and ultrasonic crystals measuring internal diameter and wall thickness. heart rate and systolic pressure were markedly increased by maximal vl but for moderate vl were minimally modified. moderate vl increased end-diastolic diameter by 5% and end-systolic diamete ... | 1981 | 7212078 |
| [correlation between the strength-duration relationship (frank-starling phenomenon) and the inotropic state of the heart]. | | 1981 | 7238932 |
| the synergistic influence of the intravascular starling forces on pulmonary microvascular solute flux in human ards. | to assess the importance of the intravascular starling forces on the pulmonary microvascular flux of solutes in ards, the clearance from blood to pulmonary edema fluid of a small-molecular-weight hydrophilic radiotracer, indium-111-dtpa, and a large-molecular-weight radiotracer, iodine-125-hsa, in patients with noncardiac pulmonary edema was measured. since permeability changes of the pulmonary microvessels in ards are likely not homogeneous, the severity of the permeability lesion according to ... | 1984 | 6748632 |
| comparison of capsular and intra-alveolar fluid pressures in the lung. | the fluid pressures measured in chronically implanted capsules were compared with fluid absorptive pressures in small degassed lung segments. capsules were implanted, and bronchiolar catheters were placed at different vertical heights in the lungs of spontaneously breathing dogs. increases in pulmonary capillary filtration pressure were produced by volume infusions of tyrode's solution and increased left atrial pressure. a vertical gradient in fluid pressures was consistently observed with more ... | 1982 | 7107455 |
| a postscript to circulation of the blood: men and ideas. | since 1964, when fishman and richards published circulation of the blood: men and ideas, guyton's model of the circulation, in which mean circulatory pressure serves as the upstream pressure for venous return, has been extended, and the concept of vascular smooth muscle tone acting like the pressure surrounding a starling resistor has been postulated. according to this scheme, the positive zero flow intercepts of rapidly determined arterial pressure-flow curves are the effective downstream press ... | 1982 | 7116585 |
| [comparative characteristics of the force and rate of myocardial contraction as indices of its contractility]. | experiments on papillary muscles of the cat heart have shown that the strength of contraction is a more adequate and sensitive criterion for evaluation of the effects of temperature, distension and contraction rate on myocardial contractility as compared to the strength of contraction. it is concluded that at the basis of the starling law and chronoinotropic mechanisms there lies the contractility control exercised through changes in the contraction rate. | 1982 | 7126830 |
| collapsing coronary stenosis--a starling resistor. | | 1982 | 7129688 |
| detrimental effects of premature use of inotropic drugs to discontinue cardiopulmonary bypass. | ten dogs underwent 45 minutes of normothermic ischemic arrest. after 15 minutes of reoxygenation, none could support the systemic circulation independently. in five dogs, we could discontinue bypass (cardic output 70 to 100 cc/kg/min) by giving dopamine (10 to 30 mcg/kg/min). in five other dogs, total cardiopulmonary bypass was prolonged for an additional 30 minutes and no dopamine was given. during control and at 15 and 45 minutes after aortic unclamping, we measured myocardial blood flow (micr ... | 1981 | 7242127 |
| transcapillary starling pressures in the fetus, newborn, adult, and pregnant adult. | we used the method of membrane osmometry to determine capillary pressure (pc), plasma protein osmotic pressure (iip), interstitial protein osmotic pressure (iiif), and interstitial free fluid pressure (pif) in subcutaneous tissue. these pressures were measured in the sheep and guinea pig fetus, newborn, adult, and pregnant adult. although there were some similarities, we found major species differences. 1) iip was a minimum in the fetus and gradually increased to a maximum with adulthood in the ... | 1981 | 7246749 |
| left atrial function in acute mitral regurgitation. factors which modify the regurgitant volume. | dynamic geometry of the left atrium was studied in open-chest dogs instrumented with ultrasonic dimension gauges for the measurement of the transverse diameter together with left ventricular dimensions and left atrial and ventricular pressures. three definite phasic changes of the left atrial diameter were observed during the cardiac cycle at the control state; shortening of left atrial diameter with atrial contraction, continuous chamber expansion during ventricular ejection, and either a reduc ... | 1981 | 7250888 |
| [hemodynamic and exercise capacity in a 72 years old patient under a ventricular and bifocal pacemaker (author's transl)]. | the results of haemodynamic, echocardiographic and bicycle exercise investigations in a 72-year-old man with a permanent complete atrioventricular block and heart failure following infarction are presented. comparative measurements were obtained under the conditions of a ventricular and an av-sequential pacemaker (pm). the ventricular demand pacemaker (vvi) was implanted three years ago and because of further impairment of cardiac performance an av-sequential pacemaker (ddd) was used to restore ... | 1981 | 7257504 |
| [the double control system of heart relaxation]. | the systolic performance of the heart is regulated by two separate mechanisms: the first involves an adaptation to load (frank-starling), and the second, variations in contractility. similarly, recent experimental studies have shown a double mechanism of control of the relaxation phase. cardiac relaxation, as regards the muscle and muscle-pump system, is governed by the constant interrelation of the sensitivity of the contractile system to conditions of load (load dependence) and by the sensitiv ... | 1980 | 6779754 |
| neural, hormonal and intrinsic mechanisms of cardiac control during acute coronary occlusion in the intact dog. | three basic mechanisms may be involved in the control of cardiac function during acute coronary occlusion: (1) neural; (2) hormonal (circulating catecholamine); and (3) intrinsic (e.g. frank--starling law). the response of intact, sedated (innovar-vet, 0.08 cc/kg), chronically instrumented dogs to a 5 min left circumflex coronary occlusion was tested to delineate the relative roles of each of the above mechanisms. first, 6 innervated and 6 cardiac denervated dogs were examined. the major differe ... | 1981 | 7264197 |
| appearance of adenosine triphosphate in the coronary sinus effluent from isolated working rat heart in response to hypoxia. | 1. a working rat heart preparation was used to study the release of adenosine-5'-triphosphate (atp) into the coronary sinus effluent in response to hypoxia. 2. the left ventricle was set to pump against an hydrostatic pressure of 65 cm water; the left atrial filling pressure was kept constant at 10 cm water. the power output of the heart at these pressures was estimated to be approximately one half of the maximum power development. 3. samples for atp assay were collected (a) 30 sec before onset ... | 1981 | 7264990 |
| functional characteristics of the renal interstitium. | the renal interstitial space analyzed as "inulin space" comprises about 13% in the rat. the starling forces of this compartment are governed by the balance between tubular and capillary fluid transport and also by the leakage of plasma proteins from the blood side. protein transport will occur in a large-pore system in the peritubular capillary membrane. during control antidiuresis, the interstitial hydrostatic pressure is 2-4 mmhg. the colloid osmotic pressure shows a larger variability but is ... | 1981 | 7270683 |
| flow through collapsible tubes at high reynolds numbers. | the pressure-flow relationships of collapsible tubes were studied utilizing the starling resistor model. reynolds numbers much higher than previously reported were used to simulate high cardiac output states. alterations which occur in vivo, including longitudinal tension, stretch, tubing diameter, length, and outflow resistance were also simulated and systematically investigated. the pressure-flow curves showed an initial rising phase, a plateau phase, as well as a late-rising phase which has n ... | 1981 | 7273367 |
| effects of isolated interventricular septal ischemia on global and segmental function of the canine right and left ventricle. | the effects of isolated septal artery ligation wee studied in 17 dogs. contraction of the interventricular septum (ivs) and the free walls of both ventricles was measured by implanting ultrasonic crystals. global ventricular function was assessed by starling function curves. following septal artery ligation, ivs shortening was immediately replaced by systolic lengthening. thirty minutes after septal artery ligation, the right ventricular (rv) stroke work (sw) was significantly depressed at end-d ... | 1981 | 7282511 |
| protein vs electrolytes and all of the starling forces. | hemodilution-induced reductions of the intravascular protein concentration in patients and experimental animals with intact capillaries do not lead to pulmonary edema, despite significant increases in the amount of extravascular water in the systemic interstitial space. the protective factors are a drop in the extravascular concentration of protein, a rise in interstitial tissue pressure, and an increase in lymph flow. if the capillary endothelium is damaged, protein leaks into the extravascular ... | 1981 | 7283703 |