It was established in rat experiments that adaptation to altitude hypoxia leads to the enhancement of immune response to sheep red blood cells and to an increase in the serum lysozyme level. Adaptation to altitude hypoxia also suppresses adjuvant arthritis and prevents arthritis-induced inhibition of antibody production.

Accumulation of primary and secondary products of lipid peroxidation (PLP) in different tissues of Wistar rats under emotional-pain stress (EPS) was studied using UV-spectrophotometry and fluorescense of Schiff bases. It was shown that under EPS the amount of PLP increased mostly in the heart and to a lesser degree in the skeletal muscle and brain. An increase in hydroperoxidases in all the organs studied was less than that in the PLP end-products, i. e. flourescent Schiff bases.

The effect of pain-induced emotional stress (PIES) on the contractile function of rat papillary muscle removed 2 h after the end of exposure to stress was studied. The velocity and amplitude of contraction and also the velocity of relaxation of the myocardium of animals exposed to PIES were reduced by more than 40%, whereas the positive inotropic effect of a high frequency of contraction was reduced by 75–86% and adrenergic reactivity was reduced about by half, although the maximal effort developed during isometric contraction was unchanged. It is suggested that during PIES a disturbance develops in the calcium transport system in the membranes and in the sarcolemmal adrenoreceptor-adenylate cyclase system.

Accumulation of primary and secondary lipid peroxidation (LPO) products were investigated by ultraviolet spectrophotometry and fluorescence of Schiff bases in various tissues of Wistar rats subjected to painful emotional stress (PES). The quantity of LPO products was shown to increase under the influence of PES mainly in the heart, and also significantly, although to a lesser degree than in the heart, in skeletal muscles and brain. The increase in content of hydroperoxides in all the organs studied was smaller than the increase in the content of fluorescent Schiff bases, the end products of LPO.

The effect of variations in the Ca concentration in the perfusate on the function of isolated hearts of control rats and of those who sustained the emotional-pain stress (EPS) was studied. It was found that the EPS sharply increased the cardiac response in the animals to shifts in the Ca concentration. A rise in the main parameters of the cardiac contractile function in response to an increased Ca concentration was more pronounced in rats after the EPS than in the controls. The sensitivity to noradrenaline decreased 2-fold as compared to the control animals. It is suggested that the growth of the relationship between the cardiac function and the Ca concentration in the animals after the EPS is caused by the damaged membranous mechanisms of Ca transport in the myocardial cells.

Adaptation of animals to high-altitude (2 km) hypoxia in the mountains prevented disturbance of cardiac contractions during emotional and pain-induced stress but did not prevent the development of gastric ulcers.

The results of experiments conducted with the nervous regulation of the heart intact indicate that body adaptation to physical exercises results in an increased capacity of the cardiac mechanisms responsible for the regulation of both the force of the contractions, and the rate of adapted animals, revealed when the neuroregulation was switched off, in contrast to those of non-adapted animals, indicate the enhancement of the autoregulation mechanism of the heart muscle under the effect of physical training.