Biomedical subjects

A M Buniatian

Publications and source records attributed to A M Buniatian.

4 recordsLinked to original sources

PubMed1986

[Electric instability of the hearts of animals with differing resistance to immobilization stress].

In 72 Wistar, August, SHR and non-linear rats, a reduction of thresholds for dysrhythmia and elongation of the cardiac cycle vulnerable phase occurred indicating obvious functional shifts following the immobilization stress. The Wistar rats revealed a greater resistance as compared to other rats: no changes of the vulnerable phase duration occurred in 80% and no difference whatever was observed in the remaining 20% of the Wistar rats. In dysrhythmia--prone animals the respective thresholds decreased most sharply and fibrillation of ventricles was mostly irreversible.

Adaptation, Physiological↗

PubMed1985

[Changes in cardiovascular functions and adrenergic innervation of the heart during immobilization stress in rats].

In 40 rats immobilized for 30 hrs, a reduction of density of distribution of the adrenergic neural terminals in myocardium occurs along with changes of the cardio-vascular functions. The death of animals in immobilization was due to a progressive drop of arterial pressure. Immediately before death the density reduction of adrenergic terminals was the most obvious. Disturbances of the cardio-vascular functions in immobilization stress seem to be related to the reduction of density of the adrenergic neural terminals distribution in the myocardium.

Adaptation, Physiological↗

PubMed1985

[Hemodynamic changes in immobilization stress].

In chronic experiments on 75 Wistar, August and randombred rats hemodynamic changes were examined during 30-hour immobilization stress. The ECG was recorded and arterial blood pressure measured. The basic hemodynamic characteristics were determined with the help of the previously implanted ultrasonic blood flow probes. Analysis of hemodynamic changes in animals resistant, adapted and prone to stress demonstrated that changes in the total peripheral resistance play the leading role in the disturbance of the arterial blood pressure control. It was established that a progressive lowering of arterial blood pressure resulting from the abruptly reduced total peripheral resistance is the main and the most frequent cause of death of animals exposed to immobilization stress. At the same time the cardiac hemodynamic component may play an essential role in the mechanism of death. This component may include either progressive bradycardia or a combination of an ischemic myocardial damage and reduced total peripheral resistance.

Adaptation, Physiological↗

PubMed1984

[Changes in adrenergic nerve plexuses of the heart during immobilization stress in the rat].

Luminescent microscopical analysis on the state of the cardiac adrenergic neural apparatus under immobilization stress has been performed in 48 rats of August and Wistar strains. The rats of August strain demonstrate a high sensitivity to the stress: 40% of the animals died during the first 4-17 h of immobilization. Cryostate sections are treated in 2% glyoxylic acid and studied in the luminescent microscope. Quantitative analysis of density distribution of the adrenergic neural terminals is performed by means of dot nets. Decreasing luminescent brightness and decreasing density by 10-15% are noted in the right auricle, and by 30-34%--in the left ventricle, comparing to that of the control. In the animals died a sudden death these parameters are even stronger (28% and 54%, respectively). The data obtained correlate to the functional disturbances of the heart activity (fluctuations of the arterial pressure, disturbances of the rhythm, ECG changes). A suggestion is made that catecholamines content in the neural terminals of the heart is of certain importance in development of the cardiovascular disturbances under immobilization stress.

Animals↗