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Biomedical subjects

A V Trubetskoĭ

Publications and source records attributed to A V Trubetskoĭ.

At least 19 recordsLinked to original sources
PubMed1990

[Coronary blood flow during stochastic stimulation of the canine heart].

Changes of mechanical activity and coronary blood flow induced by haphazard uncorrelated sequence of stimuli, were studied in the dog heart. The total coronary blood flow did not differ from one during determined regimen of the same mean frequency. Whereas relative contribution of systolic coronary flow increased and that of diastolic one decreased. The analysis of phasic blood flow in coronary vessels during potentiated and extrasystolic contractions, was performed.

Animals↗
PubMed1989

[Coronary spasm].

Explore the source record for details and available documents.

Angina Pectoris↗
PubMed1987

[Effect of noradrenaline on reactive myocardial hyperemia in dogs].

The effect of norepinephrine (NE) on reactive myocardial hyperemia (RH) after a brief (20 sec) flow arrest was studied in 9 closed-chest anesthetized dogs. NE infusion into the left ventricle resulted in the increase of RH peak during coronary flow and the elevation of the left ventricular pressure and its first derivative. The increased coronary dilatation may be explained by the activation of beta 1-adrenergic myocardial receptors. RH peak decreased later, with the coronary flow, left ventricular pressure and its first derivative returning to the control level. This RH decrease can be explained by the activation of alpha-adrenergic receptors of the coronary vessels and the competition between alpha-receptors for vasoconstriction and metabolic vasodilatation.

Animals↗
PubMed1984

[Diffusion capacity of the myocardial capillary bed in graded decrease in the coronary blood flow].

In closed chest dogs with controlled perfusion of the left coronary artery coronary blood flow was reduced by 10, 20, 30, 40, 50 and 70%. Diffusion capacity of myocardial capillary bed (permeability surface area product) decreased in all but the first (10%) series of experiments. 23-64% fall of the product occurred irrespective of coronary vessel reserve state but with respect to the degree of blood flow reduction. The amount of coronary influx possibly determined the number of perfused capillaries in the heart. Thus, 20% and more reduction of coronary blood flow cannot be compensated at the level of myocardial capillary bed.

Animals↗
PubMed1982

[Effect of nitroglycerin on myocardial function in short-term ischemia].

In acute experiments on open-chest dogs nitroglycerin (5 microgram/kg, i.v.) was injected 1 minute before a 60-second occlusion of the descending branch of the left coronary artery. At the height of ischemia nitroglycerin increased oxygen tension and produced a lowering of contractility of the deep and superficial layers of the myocardium adjacent to the zone of ischemia, this lowering was less as compared to that seen in control occlusions. Nitroglycerin did not produce marked or significant changes in oxygen tension and myocardial contractility in the central ischemic or distant areas. No significant changes in the hemodynamics were recorded either.

Animals↗
PubMed1982

[Effect of inotropic factors in the postload characteristics of the heart].

It was shown in acute experiments on cats that the post-exercise characteristics of the left ventricle plotted as a dependence between the magnitudes of the maximal blood flow velocity and systolic intraventricular pressure in health and inotropic exposures are close to the linear ones. Adrenaline shifts the post-exercise characteristics upward and to the right, increasing both the maximal magnitude of the blood flow velocity at a zero pressure (velocity component) and the maximal magnitude of the pressure at a zero blood flow (force component), the latter rising to a greater extent. Calcium chloride and obsidan cause a parallel shift of the post-exercise characteristics: the force and velocity components diminish upon obsidan administration, while with CaCl2 they increase.

Animals↗
PubMed1982

[Coronary vascular reactions of dogs to hypothalamic stimulation in acute and chronic experiments].

Stimulation of emotiogenic zones of the dog hypothalamus in acute and chronic experiments evoked the same responses in the heart and coronary vessels: an increase of the coronary vessels resistance occurred within first 5 sec of the stimulation. Acceleration of cardiac activity involved coronary vessels dilatation. Hypothalamic stimulation against the background of adrenergic betareceptor block caused an increase of coronary vessels resistance alone. Changes of arterial pressure were the same as before the block, and the change of the heart rate was less obvious. The neurogenic vasoconstriction of coronary vessels and their metabolic vasodilatation are interrelated in a complicated way: adrenergic influences activating smooth muscles of coronary vessels maintain their extravascular effects during vasodilatation of metabolic nature.

Animals↗
PubMed1981

[Experimental quantitative evaluation of the cardiac pump in function].

Experimental technique has been developed that makes it possible to change left ventricular after exercise on a wide scale during one beat at an intact circulation. The relationship between the maximal blood flow rate and left ventricular systolic pressure at permanently filled ventricle and inotropic state has been shown close to linear. This relationship (exercise characteristics) can be described by two parameters: maximal systolic blood pressure at blood flow and maximal blood flow ab zero peripheral resistance, and can be used for the assessment of the cardiac pump function.

Animals↗
PubMed1981

[Pharmacological analysis of a disorder in the mechanisms of coronary vessel reactivity in an experimental model of coronary insufficiency].

In stimulation of the heart work with inadequate perfusion, the reactivity of coronary vessels is often disturbed which is revealed by the enhancement of extravascular contraction or by the absence of an adequate vasodilatation. The analysis of disturbance mechanisms in the reactivity of coronary vessels has been carried out with the aid of two groups of pharmacologic substances, one exercising a dilatating effect on the coronary vessels and the other affecting the calcium metabolism. One group included adenosine and verapamil (as antagonists of the action of calcium) as well as etmozine-blocker of the sodium channels capable of affecting the level of Ca+2 through Na-Ca metabolism; the other group included caffeine, calcium chloride, norepinephrine. The results suggest that adaptive reactions of the coronary vessels are closely connected with the calcium metabolism in smooth muscles of the vascular wall. Hence, while using vasodilators to treat coronary insufficiency, the approach to a selection of drugs with different effects on electro-mechanical conjunction in smooth muscles of vascular wall should be differentiated.

Animals↗
PubMed1980

[2 components of ventricular contractility and their determination based on a noninvasive method].

It is suggested that a force component and a rate component should be distinguished for elaborating the quantitative values of the contractility of the heart ventricle. In experiments the first component is determined as the maximum pressure in the ventricle during isovolumic contraction, and the second component, as the maximum value of the blood flow in the ejection phase at zero afterload. Analysis of the data found in the literature and the results of the authors' experiments provides evidence that the force and rate components differ in their dependence on the hemodynamic conditions. A noninvasive method for determining the contractility components is suggested. Analysis of the clinical data and the literature confirms that the force and rate components change in a different manner in various types of pathological conditions.

Animals↗