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Biomedical subjects

V B Brin

Publications and source records attributed to V B Brin.

18 recordsLinked to original sources
PubMed1991

[The effect of parathormone on the reactivity of the renal blood flow to noradrenaline in normotensive and spontaneously hypertensive rats].

The effect of parathyroid hormone on the renal cortex and medulla hemodynamics and on systemic circulation was studied after various doses of i.v. norepinephrine in normotensive and spontaneously hypertensive rats. The experiments were performed in anesthetized and intact rats, and 12-14 hrs after parathyroid hormone i.m. injection. The latter caused similarly directed changes in the renal hemodynamics in normotensive and spontaneously hypertensive rat: the decrease of the renal cortex and the increase of the renal medulla blood flows. Parathyroid-induced response to norepinephrine in the renal cortex hemodynamics was similar in both types of rats reducing the effect. The shifts of the renal medulla response to norepinephrine were opposite in normotensive (increase) and spontaneously hypertensive rats (decrease). Parathyroid hormone increased the vascular resistance, decreased the cardiac output and reduced vascular and pressor responses to norepinephrine in normotensive rats. The parathyroid hormone dramatically decreased vascular resistance, slightly increased the cardiac output and the vascular and pressor responses to norepinephrine in spontaneously hypertensive rats.

Animals↗
PubMed1991

[The effect of calcitonin on the mechanisms of urine formation and sodium excretion in normotensive and spontaneously hypertensive rats].

The effects of the pig calcitonin on the kidney excretory function in normotensive (NR) and spontaneously hypertensive rats (SHR) were examined. Calcitonin injection in the dose of 0.6 U/100 g of the body mass in NR and SHR in the conditions of 6-hour spontaneous diuresis caused the increase in the urination volume due to the inhibition of the tubular water reabsorption and growth of the glomerular filtration rate. The important role in the mechanism of the decrease in the water reabsorption in SHR plays the decrease in the content of vasopressin in the blood and urea in the kidney interstitium while in NR a more marked inhibition of the water reabsorption is caused by the decrease in the concentration of both urea and sodium in the kidney layers. The natriuretic effect of calcitonin was noticed only in NR.

Animals↗
PubMed1990

[The effect of parathormone on the reactivity of the cardiovascular system to angiotensin-2 in normotensive and spontaneously hypertensive rats].

The effect of parathyroid hormone (2 units/100 g) on hemodynamic response to various doses of i.v. angiotensin-2 (16 ng/100 g; 20 ng/100 g; 24 ng/100 g) was studied in normotensive and spontaneously hypertensive rats. The effect involved a decrease of the minute blood volume, stroke volume, and an increase of total peripheral resistance in normotensive rats. Parathyroid hormone decreased total peripheral resistance and increased the minute blood volume and the heart rate in spontaneously hypertensive rats. Angiotensin-2 raised the arterial pressure in normotensive rats. In presence of parathyroid hormone, the angiotensin-2 pressor effect was quite obvious in normotensive rats whereas in spontaneously hypertensive rats angiotensin-2 effect caused the greatest rise of arterial pressure as a result of a considerable dose-dependent rise of total peripheral resistance, the cardiac output showing a tendency towards a reduction.

Angiotensin II↗
PubMed1978

[Effect of the alpha-adrenoblocker pyrroxan on systemic hemodynamics in puppies and dogs with vasorenal hypertension].

Vasorenal hypertension was induced in 2--3-month-old puppies and adult dogs by stricture of both renal arteries. 1.5 mg/kg of pyrroxan was injected intravenously 3 and 14 days later. A reduction of increased arterial pressure was noted both in adult dogs and in puppies, to the subnormal level in the latter. Hypotensive effect of the preparation was connected in adult animals with diminution of the general peripheral vascular resistance and in puppies, besides, with reduction of cardiac output. Pyrroxan injection was accompanied in all the animals with tachycardia, reduction of the phase of isometric contraction and activation of myocardial contractility.

Adrenal Medulla↗
PubMed1978

[Hemodynamic effects of obzidan in vasorenal hypertension in dogs in ontogeny].

Vasorenal hypertension was reproduced in experiments on 18--22 day-old and 2--3-month-old puppies and on sexually-mature dogs by bilateral stenosis of the renal arteries. Two weeks later all the animals were given intravenous infusion of obzidan in a dose of 2 mg/kg. The arterial pressure, the minute and systolic volumes (MV, SV), total peripheral resistance (TPR), and the work, strength, and phase structure of the left ventricle were recorded. In animals aged 18--22 days with elevated pressure, obzidan infusion promoted its normalization, led to a decrease in the increased MO to subnormal values, a decrease in TPR and the heart beat rate, and normalization of the increased SV. In puppies aged 2--3 months, obzidan normalized the pressure by causing a fall in the minute output which was already reduced in hypertension, and a certain decrease in TPR with hardly any changes occurring in SV. In adult dogs, despite a sharp decrease in MV, arterial pressure did not significantly change due to the increase in TPR. Energy expenditure per each liter of MV was normalized by obzidan only in puppies.

Age Factors↗
PubMed1977

Alterations of systemic haemodynamics in experimental renovascular hypertension in dogs of different ages.

Renovascular hypertension [bilateral simultaneous stenosis of renal arteries] was produced in 35 dogs of different ages [18--22 days, 2--3 months, 3--5 years]. On days 3 and 14 of renal ischaemia, the alterations were investigated that had occurred in the arterial pressure, cardiac output, stroke volume, total peripheral vascular resistance [TPVR], left ventricular work, and other haemodynamic indicators. It was found that the more marked elevation of arterial pressure in puppies was connected not only with increased TPVR, but also with enhanced cardiac output and stroke volume, whereas in mature animals at increased TPVR the cardiac output and stroke volume were reduced. The authors ascribe the differences in haemodynamic changes to age-dependent differences in intracardiac compensation, autonomous regulation of heart function, and the functional state of the renin-angiotensin system.

Age Factors↗
PubMed1977

[Change in systemic hemodynamics under the influence of vasopressin in dogs during ontogenesis].

Experiments were conducted on dogs (18-22 days, 2-3-month-old and adult). The central hemodynamics indices were studied after intravenous administration of 0.8 U/kg of synthetic vasopressin. The pressor effect was mostly expressed in adult dogs, and bradycardia--in 18--22-days-old puppies. All dogs displayed an increase of the total peripheral resistance accompanied by reduction of the minute output. External work of the left ventricle and expenditure of the energy by the heart rose in adult dogs. As to puppies, a reduction of the cardiac output and of the external heart work was accompanied by a lesser increase of energy expenditure.

Animals↗
PubMed1975

[Dynamics of contraction of the left and right ventricles of the heart (according to kinetocardiography data) in the development of renovascular hypertension in dogs of various ages].

Kinetocardiograms of the left and the right ventricles of the heart were recorded in puppies and adult dogs during development in them of experimental renovascular hypertension. Development of hypertension in adult dogs led to the shortening of ejection period, and in puppies--to its prolongation. The vector analysis of kinetocardiograms demonstrated in adult dogs the appearance of the syndrome of hypodynamics of the left ventricle replaced later by the syndrome of high diastolic pressure. In the puppies' left ventricle there appeared the phasic syndrome of high diastolic pressure replaced by the syndrome of stenosis of the exit tract. The phasic structure of the cycle of the right ventricle is characterized by the appearance of the syndrome of hyperdynamia detectable earlier in adult dogs.

Age Factors↗
PubMed1975

[Changes in systemic hemodynamics following administration of synthetic angiotensin II to dogs of different ages].

Experiments were conducted on dogs aged 18-22 days, 2-3 month-old and adult dogs. Arterial blood pressure, cardiac output, heart rate and total peripheral resistance during the infusion of synthetic angiotensin-II-amide in a dose of 2 mug/kg per minute were studied. An increase of arterial pressure in adult dogs during the action of angiotensin-II was connected with the elevation of the total peripheral resistance. An increase of the total peripheral resistance and also of the cardiac output was seen in the puppies. The differences in the degree of increase of the arterial blood pressure in adult dogs and puppies were not marked.

Age Factors↗
PubMed1975

[Reaction of the neurosecretory system of dogs with reno-vascular hypertension in the postnatal ontogenesis].

In dogs of different age with simulated renovascular hypertension neurosecretion of the hypothalamo-neurohypophysial system was studied. Experiments were conducted with puppies 18-22 days, 11/2-3 months and dogs 3-5 years old. It was established that in the ontogenesis of dogs the differentiation of neurons in the supraoptic nucleus occurred earlier than that of cells in the paraventricular nucleus. The simulation of hypertension accelerates the differentiation of tbe neurosecretory cells. The development of arterial hypertension leads to prevalence of precesses of the neurosecretory material outflow over the latter's synthesis, irrespective of the maturity of the neurosecretory system. With the arterial pressure stabilized at a high level a concordance between an elevated synthesis of the neurosecretion and its increased outflow is noted. Visual evaluation of the activity is supported by the results of cellular micrometry.

Age Factors↗
PubMedDate not supplied

[Effect of adrenoreceptor blockade on plasma renin activity during postnatal ontogenesis in dogs].

The activity of renin in the blood plasma of 10-, 18--22-day and 2--3-month puppies is higher than in adult dogs. Blocking beta adrenoreceptors in 18--22-day, 2--3 month and adult animals decreases the activity of renin. Hypotensive effect following beta adrenergic block in 10-day puppies and alfa adrenergic block in puppies of all age groups is accompanied by the increase in renin activity. In early ontogenesis, the leading role in regulation of renin secretion belongs to changes in renal hemodynamics.

Adrenergic alpha-Antagonists↗
PubMedDate not supplied

[Effect of obsidan on the systemic hemodynamics of dogs in ontogeny].

Investigations on dogs of different age have brought evidence that intravenous administration of 2 mg/kg of obsidan (propranolol hydrochloride) causes in 18-22-day old puppies a fall of arterial pressure due to a reduced cardiac ejection with little changing total vascular peripheral resistance. The frequency of the rhythm and conduction in the heart are slowed down. In dogs aged 3-5 years the arterial pressure remains unchanged, since the diminution of the cardiac output is attended by a greater vascular resistance.

Age Factors↗