Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
|---|
| influence of hypertonic-hyperoncotic solution and furosemide on canine hydrostatic pulmonary oedema resorption. | 1. this study aimed at enhancing the clearance of experimental hydrostatic pulmonary oedema in dogs using hypertonic-hyperoncotic solution (hhs) and furosemide. 2. anaesthetized dogs (n = 20) were mechanically ventilated with a positive end-expiratory pressure of 10 cmh2o (1.0 kpa). 3. hydrostatic pulmonary oedema was induced by inflating a balloon inserted into the left atrium and simultaneously infusing isotonic saline rapidly. oedema formation was terminated by deflating the balloon and reduc ... | 1992 | 1302272 |
| lymphatic versus nonlymphatic fluid absorption from the peritoneal cavity as related to the peritoneal ultrafiltration capacity and sieving properties. | in this article we discuss the role of capillary fluid absorption via starling mechanisms (the transcapillary hydrostatic pressure gradient opposed by the colloid osmotic pressure gradient as multiplied by the capillary uf coefficient) vs. lymphatic fluid absorption as determinants of the total fluid loss from the peritoneal cavity during continuous ambulatory peritoneal dialysis (capd). we also mention that, under nonsteady state conditions, there is in addition some net absorption of fluid int ... | 1992 | 1308683 |
| [influence of transient and sustained increase of blood pressure on the 1st temporal derivative of the ventricular pressure]. | to analyze the influence of transient and sustained elevations of arterial pressure (ap) on the rate of rise of the left ventricular pressure (dp/dt). | 1992 | 1340722 |
| the identification of sex in the starling sturnus vulgaris using a molecular dna technique. | female birds can be identified through the presence of a w-chromosome. we describe a procedure for amplifying a w-linked dna marker in the starling (sturnus vulgaris) by the polymerase chain reaction (pcr) so allowing the diagnosis of sex in this species. the technique is sensitive, allowing even the smallest chicks to be sexed from a blood sample. the method possesses a positive internal control to ensure accuracy. it is also applicable to the spotless starling (s. unicolor) but not to two bird ... | 1992 | 1344995 |
| effect of dexmedetomidine, an alpha 2-adrenergic agonist, in the isolated heart. | dexmedetomidine (dm) was studied in the isolated dog heart in the form of a starling heart-lung preparation, (hlp). hearts were subjected to increased loading by (a) increasing cardiac output, and (b) increasing systemic resistance. results are depicted by cardiac function curves, prepared by plotting left atrial pressure against either systemic cardiac output or mean arterial pressure. dm, given in divided doses up to 44 micrograms, had no effect on heart rate or cardiac function, nor did injec ... | 1992 | 1353991 |
| the metabolic output of avian (sturnus vulgaris, calidris alpina) adipose tissue liver and skeletal muscle: implications for bmr/body mass relationships. | 1. the oxygen uptake rate of avian adipose tissue, liver and skeletal muscle slices were measured. 2. the energy consumption of fat was less than one tenth that of liver and muscle. 3. thus, interspecific allometric equations for the prediction of basal metabolic rate from body mass will not be accurate throughout the avian annual cycle unless changes in body composition are taken into account. | 1992 | 1359954 |
| effect of afterload and beta-adrenergic blockade on nonischemic myocardial contraction pattern. | we studied how changes in afterload affect regional contraction in the anterior wall of the left ventricular after circumflex coronary arterial (cfx) occlusion and subsequent beta-adrenergic blockade in pentobarbital sodium-anesthetized cats. regional function was determined by orthogonal sonomicrometry. cfx occlusion produced nonuniform hyperkinesis in the nonischemic anterior wall; shortening of circumferential segments increased from 10.1 to 14.1% (p < 0.001), whereas shortening of longitudin ... | 1992 | 1362331 |
| comparative response of nestling european starlings and red-winged blackbirds to an oral administration of either dimethoate or chlorpyrifos. | red-winged blackbird (agelaius phoeniceus; blackbird) and european starling (sturnus vulgaris; starling) nestlings were dosed with either 2.0 mg/kg body mass chlorpyrifos, 50.0 mg/kg body mass dimethoate, or a propylene glycol carrier in situ. four growth measurements (body mass, culmen, tarsus, wing) were recorded from nestlings to determine if these organophosphorus compounds caused perturbations in development at sublethal concentrations. blackbird nestlings were more sensitive to chlorpyrifo ... | 1992 | 1380993 |
| responses of isolated rabbit thoracic aortae to endothelin-1 and several vasoactive substances. a new blood perfusion circuit under the controlled conditions of resistance and flow. | analysis of the reactivity of isolated rabbit thoracic aorta to isoproterenol and norepinephrine injected into a blood perfusion circuit intraarterially (i.a.) under controlled conditions of resistance and flow using conscious support rabbits revealed that with pressure loads of 10-20 mmhg for a vessel-holding chamber and 60 mmhg for a starling pneumatic resistance set, a suitable vasodilation or vasoconstriction can be obtained. this leads us to assume that the system could be used to assess th ... | 1992 | 1392057 |
| perception of cliff swallow calls by birds (hirundo pyrrhonota and sturnus vulgaris) and humans (homo sapiens). | we tested for species differences in the perception of the cliff swallow chick begging call. one cliff swallow (hirundo pyrrhonota), 3 european starling (sturnus vulgaris), and 3 human (homo sapiens) subjects were trained on go-no-go or repeating background tasks to discriminate between all possible stimulus pairs, measured by percentage of correct response and latency. we used multidimensional scaling to convert the similarity measures into a 2-dimensional map for each subject. most of the maps ... | 1992 | 1395493 |
| the emergence of endocrinology. | endocrinology was recognized as a new branch of biological science mainly as a result of events which took place between about 1890 and 1905, but ideas and discoveries dating from antiquity contributed to it also. experiments supporting the concept of internal secretions by the testicles were described by aristotle (4th c. b.c.) and by hunter (18th c.) and berthold (19th c.). in 1855 bernard described glucose as an internal secretion of the liver and addison reported the effects of adrenal disea ... | 1992 | 1398153 |
| a simple distensible vessel model for interpreting pulmonary vascular pressure-flow curves. | a simple distensible vessel model was developed for the purpose of interpreting the vascular pressure-flow curve in the zone 3 lung. the model-governing equation has two parameters: r0, representing the hemodynamic resistance of the undistended pulmonary vascular bed, and alpha, representing the distensibility of the resistance vessels. to evaluate the model, the governing equation was used in a nonlinear regression analysis of the pressure-flow data from isolated dog lung lobes. the dependency ... | 1992 | 1400067 |
| changes in pericardial pressure during the perinatal period. | to determine how the tissues that surround the heart affect diastolic and systolic function during the perinatal period, we studied the pressure-diameter relation of the left ventricle in partially delivered fetal lambs. | 1992 | 1423972 |
| cytoarchitectonic organization and morphology of cells of the field l complex in male zebra finches (taenopygia guttata). | the organization of the field l complex, a thalamorecipient auditory region in the telencephalon of birds, was examined in nissl and golgi preparations of male zebra finches (taenopygia guttata). the field l complex comprises five cytoarchitectonic subdivisions: l1, l2a, l2b, l3, and l, although the border between l and l2b is not distinct. l2a is a plate extending dorsocaudally from the dorsal medullary lamina in the caudal neostriatum. l1 lies on the anterodorsal border and l3 lies on the post ... | 1992 | 1447407 |
| mechanical determinants of myocardial oxygen consumption with special reference to external work and efficiency. | the aim of the study was to investigate the ambiguous effect of left ventricular afterload on myocardial work, oxygen consumption, and efficiency. | 1992 | 1451165 |
| diastolic vibration improves systolic function in cases of incomplete relaxation. | incomplete relaxation of the left ventricle (lv) affects lv filling, but the subsequent effect on lv systolic function remains unclear. we attempted to improve relaxation by applying oscillatory mechanical perturbation during diastole (diastolic vibration) and examined the extent to which systolic function improved. | 1992 | 1451267 |
| frequency discrimination in the european starling (sturnus vulgaris): a comparison of different measures. | frequency-difference limens (dl) were determined in a songbird, the european starling (sturnus vulgaris), for stimuli differing in the type of frequency change. four different types of frequency change were studied: an increase in frequency between pulsed tones (type fsu), a single sinusoidal sweep upward (type ssu) starting in the center of an 800 ms signal, an asymmetrical periodic sinusoidal frequency modulation that extended only above the reference frequency (type asfm), and a symmetrical p ... | 1992 | 1464574 |
| functional significance of the frank-starling mechanism under physiological and pathophysiological conditions. | the functional significance of the frank-starling mechanism under physiological and pathophysiological conditions is discussed, based mainly on animal experiment results (in the dog, pig and rat). the dependence of individual stroke volume on end-diastolic volume can be described adequately using frank's diagram. this can be illustrated by varying filling pressure (respiratory cycle, vascular tone in the capacitance system, body position, circulating blood volume) and by alterations in the durat ... | 1992 | 1478214 |
| heart size and maximal cardiac output are limited by the pericardium. | we tested the hypothesis that the pericardium, by restricting heart size, limits maximal cardiac output and oxygen consumption. we studied 15 pigs. five underwent maximal treadmill running before and 14-21 days after thoracotomy and pericardiectomy; these pigs also received sequential volume infusions to determine end-diastolic pressure-dimension relationships. five underwent maximal treadmill running before and 14-21 days after thoracotomy (pericardium undisturbed) to determine the effect of th ... | 1992 | 1481894 |
| anion manipulation: a new antiarrhythmic approach. action of substitution of chloride with nitrate on ischemia- and reperfusion-induced ventricular fibrillation and contractile function. | the role of anions in the initiation of ischemia- and reperfusion-induced arrhythmias is unknown. we examined the antiarrhythmic effects of isotonic substitution of extracellular cl- with no3- by using the rat langendorff preparation (n = 12 per group). during 30 minutes of regional ischemia, the incidence of ventricular fibrillation (vf) was reduced from 50% in hearts perfused with control solution (containing a cl-:no3- ratio of 100:0) to 25%, 0% (p less than 0.05), 0% (p less than 0.05), and ... | 1992 | 1551189 |
| auditory perception of conspecific and heterospecific vocalizations in birds: evidence for special processes. | budgerigars (melopsittacus undulatus), canaries (serinus canaria), and zebra finches (poephila guttata castanotis) were tested for their ability to discriminate among distance calls of each species. for comparison, starlings (sturnus vulgaris) were tested on the same sounds. response latencies to detect a change in a repeating background of sound were taken as a measure of the perceptual similarity among calls. all 4 species showed clear evidence of 3 perceptual categories corresponding to the c ... | 1992 | 1555398 |
| ischemia-induced depressed systolic thickening is transiently augmented by remote coronary occlusion. | to determine if ischemia-induced depressed myocardial thickening can be augmented by remote coronary occlusion, posterior wall function (pulsed doppler crystal) was measured before and after left anterior descending coronary artery occlusion in the presence of reduced circumflex coronary artery flow (of sufficient severity to reduce resting function) in an anesthetized open-chest canine preparation in which the circumflex was pump-perfused with carotid arterial blood. left anterior descending co ... | 1992 | 1571984 |
| estimation of total body fluid shifts between plasma and interstitium in man during extracorporeal circulation. | fluid transport between plasma and interstitium during extracorporeal circulation was studied in seven patients undergoing aortocoronary bypass grafting. the absolute shifts in plasma volume during hypothermia were determined as the difference between input and loss of fluid and the changes in blood volume. the change in haemoglobin concentration due to acute haemodilution when starting extracorporeal circulation was used to calculate the absolute blood and plasma volume. the starling equation f ... | 1992 | 1574974 |
| azimuthal sound localization in the european starling (sturnus vulgaris): i. physical binaural cues. | the physical measurements reported here test whether the european starling (sturnus vulgaris) evaluates the azimuth direction of a sound source with a peripheral auditory system composed of two acoustically coupled pressure-difference receivers (1) or of two decoupled pressure receivers (2). a directional pattern of sound intensity in the free-field was measured at the entrance of the auditory meatus using a probe microphone, and at the tympanum using laser vibrometry. the maximum differences in ... | 1992 | 1583608 |
| pressure-flow relationships of the pulmonary circulation during endotoxin infusion in intact dogs. | we aimed to characterize the effects of an endotoxin insult (escherichia coli 0127:b8) on the relationships between pulmonary vascular pressure and flow in intact dogs. to achieve this goal, multipoint plots of total pressure gradient, arterial pressure gradient, and venous pressure gradient vs. flow were generated by graded inflation of a right atrial balloon, which was used to vary flow. the partitioning of the total pressure decrease across the pulmonary vasculature (total pressure gradient = ... | 1992 | 1617970 |
| single perturbed beat vs. steady-state beats for assessing systolic function in the isolated heart. | single-beat and steady-state techniques for evaluating end-systolic pressure-volume relationship (espvr) and frank-starling mechanism (fsm) in the crystalloid-perfused isolated rabbit heart were compared. in the single-beat technique, a train of stable isovolumic beats was interrupted with a single perturbed beat that either ejected against various levels of imposed isobaric load (espvr protocol) or beat isovolumically against various levels of end-diastolic volume (v(ed); fsm protocol). in stea ... | 1992 | 1621824 |
| responses of the cardiac transplant patient to exercise and training. | total denervation persists in the human heart following cardiac transplantation. at rest, there is some increase of heart rate and blood pressure. with a low normal cardiac output. the donor heart remains capable of a satisfactory acute response to exercise, based upon an increase of venous return (acting through the frank-starling mechanism) and slower chronotropic and inotropic responses to circulating catecholamines. during submaximal exercise, the stroke volume is greater than normal, but th ... | 1992 | 1623890 |
| regional contractile performance during acute ischemia in porcine right ventricle. | studies of regional ischemia in the canine left ventricle (lv) have shown augmented systolic segmental shortening in nonischemic regions. to characterize these responses in the right ventricle (rv), acute occlusions of the right coronary artery (rcao) were produced in anesthetized pigs. orthogonal pairs of ultrasonic segment-length crystals were implanted in the mid-rv free wall (ischemic region) and in the outflow tract (nonischemic region). rv pressure-area work loops were generated during inf ... | 1992 | 1636753 |
| 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 |
| 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 |
| an evaluation of pulsus alternans in closed-chest dogs. | pulsus alternans is a condition in which the arterial pressure generated by the heart oscillates between two levels on a beat-to-beat basis. we evaluated the onset of pulsus alternans in chronically instrumented dogs subjected to tachycardia and inferior vena caval occlusion. during pulsus alternans, the left ventricular (lv) end-diastolic volume (edv) was larger before the strong beats (28.7 +/- 5.3 vs. 25.9 +/- 4.5 ml, p less than 0.001 by paired t test), suggesting that the frank-starling mec ... | 1992 | 1733317 |
| setting complex tasks to single units in the avian auditory forebrain. i: processing of complex artificial stimuli. | in the auditory forebrain (field l) of the european starling (sturnus vulgaris), single unit responses were recorded for a wide range of complex stimuli, comprising different forms of amplitude and frequency modulation. about two-third of the units locked to sinusoidal modulation regardless of whether frequency (sfm) or amplitude (sam) was modulated. on average, however, frequency led to stronger synchronization. both the proportion of phase locking and its mean strength showed a low-pass depend ... | 1992 | 1733914 |
| regulation of pancreatic exocrine secretion. | the exocrine pancreas secretes throughout 24 hours. in both interdigestive and postprandial states, pancreatic secretion is regulated by neural and hormonal actions, and neurohormonal interactions. at the turn of this century, the prevailing theory of pavlov (1) that pancreatic exocrine secretion was exclusively regulated by secretory fibers in both vagi and splanchnic nerves was refuted by bayliss and starling in 1902, who put forward their hypothesis that pancreatic secretion was stimulated by ... | 2002 | 1744449 |
| chemical repellency in birds: relationship between chemical structure and avoidance response. | we examined how molecular structure of 24 anthranilate and benzoic acid derivatives correlated with drinking behavior in european starlings sturnus vulgaris. the effectiveness of bird repellents was associated with basicity, the presence of an electron-donating group in resonance with an electron-withdrawing carboxylic group on a phenyl ring, and a heterocyclic ring in the same pi cloud plane as the phenyl ring. of the benzoic acid derivatives tested in this study, methyl, ethyl, dimethyl, and l ... | 1991 | 1744613 |
| 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 |
| 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 |
| effects of plagiorhynchus cylindraceus (acanthocephala) on the energy metabolism of adult starlings, sturnus vulgaris. | although the relationship between intestinal parasitism, the ingestion and use of energy, and host survival is expected, little work has been done to outline the effect of such organisms upon their host's nutritional requirements in an ecological context. this study is the first to demonstrate that an intestinal helminth previously reported to be of little or no histopathological consequence, plagiorhynchus cylindraceus, has a significant detrimental impact upon the flow of food energy through a ... | 1991 | 1780177 |
| 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 |
| effect of daylength on the rate of recovery of photosensitivity in male starlings (sturnus vulgaris). | four groups of castrated photorefractory starlings were transferred from a photoperiod of 18 h light/day (18 l) to photoperiods of 6 l, 8 l, 11 l or 12 l. a control group was kept on 18 l. plasma concentrations of luteinizing hormone (lh) were low in all groups initially. the first significant increase in lh, which signals the recovery of photosensitivity, occurred after 4 weeks in the groups on 6 l and 8 l, after 8 weeks in the 11 l group and after 13 weeks in the 12 l group. there was no incre ... | 1991 | 1787473 |
| 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 |
| 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 |
| 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 |
| thyroxine treatment induces changes in hypothalamic gonadotrophin-releasing hormone characteristic of photorefractoriness in starlings (sturnus vulgaris). | photosensitive intact male starlings were transferred from short days (8l:16d) to 11l:13d for 16 weeks, and were therefore sexually mature. experimental groups were (i) held under 11l:13d and given exogenous thyroxine dissolved in the drinking water for 6 weeks or (ii) given thyroxine for 6 weeks and then transferred from 11l:13d to long days (18l:6d) for a further 6 weeks, while control groups were transferred to long days (18l:6d) either (iii) for 6 or (iv) for 12 weeks, or were (v) maintained ... | 1991 | 1874391 |
| 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 |
| [graded hypercapnia in the postoperative evaluation of central hemodynamics in cardiosurgical patients]. | 117 patients were examined in the early period after operation on an open heart (aortocoronary shunt and correction of acquired valvular heart diseases). the hemodynamic values were studied by direct methods with catheterization of the right parts of the heart and pulmonary artery. the catheter was introduced into the left atrium during the operation by transseptal puncture. in the absence of the latter, pulmonary capillary wedge pressure was measured. the loading volume test (lvt) was conducted ... | 2002 | 1906558 |
| 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 |
| characterization of covalent binding of [14c]-2-chloro-4-acetotoluidide to microsomes of starling liver and kidney. | in this study, we have characterized the covalent binding of [14c]-2-chloro-4-acetotoluidide (cat) radioactivity to microsomes of starling liver and kidney. the maximal velocity (vmax) of covalent binding and apparent michaelis constant (km) for both tissues were similar. the vmax for liver and kidney were 52.8 and 68.9 pmol/min/mg protein, and the apparent kms were 0.54 and 0.87 mm, respectively. the covalent binding of radioactivity to heat-denatured microsomes of liver and kidney was reduced ... | 1991 | 1941900 |
| 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 |
| studies of myocardial protection in the immature heart. iv. improved tolerance of immature myocardium to hypoxia and ischemia by intravenous metabolic support. | thirteen immature puppies (2 to 4 kg) underwent 1 hour of acute hypoxia (oxygen tension 25 to 30 mm hg), followed by 45 minutes of normothermic global ischemia on total vented bypass with normal blood reperfusion. ventricular function was assessed by inscribing starling function curves and measuring stroke work indices before hypoxia and after reperfusion. seven puppies (control) received normal saline infusion at 4 ml/kg/hr. six other puppies received a 4 ml/kg/hr intravenous infusion of glutam ... | 1991 | 1986167 |
| 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 |
| myocardial metabolic effects of in vivo hydralazine treatment of streptozotocin-diabetic rats. | we determined myocardial pumping capacity, glucose oxidation, and mechanical response to ischemia in streptozotocin-diabetic rats treated for 4 wk with or without hydralazine (0.5 mg/g of chow). plasma triglycerides and cholesterol were decreased 73 and 50%, respectively, in the treated animals. blood glucose levels were greater than 400 mg/100 g in both groups. hearts were perfused in the working configuration with buffer containing 5 mm [u-14c]glucose. starling curves were constructed by incre ... | 1991 | 1996694 |
| 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 |
| 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 |
| indirect estimation of filtration variables in rat lungs calculated by protein concentration or osmotic pressure method. | we reported a new way for estimating filtration variables: k(filtration coefficient), ppmv (perimicrovascular pressure) and sigma (protein reflection coefficient), from 3 different measurements of weight gain at two protein concentrations of perfusate (cmv) and at two vascular pressures (pvasc). we used the starling equation for calculating those variables using two different formulas which expressed that all protein moves by convection. in this report, we compared those two formulas: 1) 1--sigm ... | 1991 | 2048125 |
| mechanism of sustained mechanical alternans. effect of variations in ventricular billing volume. | this study investigations the phenomenon of sustained mechanical alternans (sma) through the use of quantitative criteria. discrete analysis is used to demonstrate that the hemodynamic variables during sma are governed by a simple mathematical relation. the analysis shows that the value of the slope created by the two alternating beats on the stroke volume (sv)-end-diastolic volume (edv) plane is gamma = (mu - 1) (1 + beta)/(mu - beta), where mu = svs/svw, and svs and svw denote the strong and w ... | 1991 | 2054940 |
| alterations in myocardial contractility in conscious dogs with dilated cardiomyopathy. | we investigated the changes in left ventricular (lv) geometry and myocardial contractility in eight conscious chronically instrumented dogs studied before and after the development of dilated cardiomyopathy induced by rapid ventricular pacing. significant increases (p less than 0.01) were observed in cardiac dimensions in both the lv long and short axes and in end-diastolic volume (control: 53 +/- 1 ml; cardiomyopathy: 76 +/- 2 ml) and end-systolic volume (control: 27 +/- 2 ml; cardiomyopathy: 5 ... | 1991 | 2058725 |
| temporal modulation transfer functions in the european starling (sturnus vulgaris): i. psychophysical modulation detection thresholds. | temporal modulation transfer functions (tmtf) were obtained from four european starlings (sturnus vulgaris) using a psychophysical go/nogo procedure combined with the method of constant stimuli. the tmtf for a continuous, broad-band noise of 55 db spl had a low-pass characteristic with a cut-off frequency of 123 hz. for an 800 ms gated stimulus of the same sound-pressure level, the tmtf had the shape of a band-pass filter with the most sensitive modulation frequency at around 20 hz. at 75 db the ... | 1991 | 2061200 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| [long-term monitoring of changes in contractility of the left ventricular wall in patients with myocardial infarct]. | using two-dimensional echocardiography, the authors made a one-year investigation of left ventricular function in a group of patients after a first transmural myocardial infarction. they evaluated subjectively and quantitatively changes in the contractility and the development of the diastolic area of the left ventricle. they revealed a certain improvement of the contractility, probably as a result of the development of a collateral circulation and altered structure of the infarction focus assoc ... | 2000 | 2327080 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| integrative nature and time course of cardiovascular alterations in the diabetic rat. | time-dependent alterations in integrated cardiovascular function were assessed in the streptozotocin-diabetic rat. hemodynamic measurements in the intact, anesthetized animal revealed significant and progressive reduction in heart rate after 2, 4, and 8 weeks of diabetes. myocardial contractility (+ dp/dt) and rate of relaxation (-dp/dt) were preserved at 2 weeks, but progressively declined thereafter. integrative mechanisms maintained mean arterial blood pressure within normal limits at all tim ... | 1986 | 2422482 |
| sensory projections to the nucleus basalis prosencephali of the pigeon. | the afferent pathways to the nucleus basalis prosencephali of the pigeon were studied by use of the horseradish peroxidase (hrp) technique. it was confirmed that this nucleus receives a direct pathway from the nucleus sensorius principalis nervi trigemini and that, as in the starling, it receives a direct input from the nucleus lemnisci lateralis, pars ventralis, an auditory relay. totally novel is the finding that the nucleus basalis prosencephali is the target of a direct pathway originating i ... | 1986 | 2428501 |
| the effects of intravenous infusion of solutions with different colloid osmotic pressures on rat mesenteric lymph pressure. | the effects of intravenous infusion of solutions of varied colloid osmotic pressure on mesenteric lymph pressure were measured by a glass micropipette. the lymph pressure was 4.0 +/- 1.6 cm h2o between the second and third valve of rat mesenteric lymphatic vessels with diameter of 101 +/- 25 micron (mean +/- sd). intravenous infusion of 1 ml/100g body weight (b.w.) of isotonic saline, 5% glucose solution, and 20% glucose solution increased the lymph pressure by 1.6 +/- 0.5 cm h2o, 1.5 +/- 0.3 cm ... | 1986 | 2431233 |
| immunohistochemical localization of neuropeptides in the vocal control regions of two songbird species. | immunohistochemistry was used to map the distribution of four neuropeptides in song control regions of two songbird species, the european starling (sturnus vulgaris) and the song sparrow (melospiza melodia). we searched for positively stained cell bodies or apparent terminals containing vasoactive intestinal peptide (vip), methionine-enkephalin (met), cholecystokinin (cck), and substance p (sub p). intraventricular colchicine pretreatment was administered to enhance the visualization of peptide- ... | 1988 | 2452178 |
| the importance of nervous and humoral mechanisms in the control of cardiac performance in the atlantic cod gadus morhua at rest and during non-exhaustive exercise. | the nervous regulation of heart rate and stroke volume in the atlantic cod gadus morhua was investigated both in vivo, during rest and exercise, and in vitro. the cholinergic and adrenergic influences on the heart were estimated in experiments with injections of atropine and sotalol. at rest the cholinergic and adrenergic tonus on the heart were 38% and 21%, respectively (ratio 1.81:1). at the end of an exercise period, the cholinergic tonus had decreased to 15% but the adrenergic tonus had incr ... | 1988 | 2463325 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |