[Morphometric characterization of hepatocytes during adaptation to extreme Antarctic factors].

The dynamics of ultrastructural changes in the hepatocytes of albino rats after prolonged influence of extreme Antarctic factors had been studied using the morphometric method. It was found that at the early stage of the experiment (7-45 days) the intracellular homeostasis in the hepatocytes was disturbed owing to a pronounced decrease in energy sources and plastic reserves (the decrease in numerical and volume density of the mitochondria, the reduction of the rough endoplasmic reticulum volume and the dilatation of its cisterns, the increase in the volume of the smooth endoplasmic reticulum). The following stages (up to 180 days) were characterized by a practically complete restoration of energy-plastic potential of the hepatocytes; at the conclusive stage of the experiment (270 days) the exhaustion of energy and, especially, of plastic reserves of the hepatocytes was noted (the significant decline in numerical density of the mitochondria and the relative volume of the rough endoplasmic reticulum).

[Dynamics of morphometric indicators of rat testes during adaptation to high-altitude in the Antarctic regions with subsequent dysadaptation]. / Dinamika morfometricheskikh pokazatelei semennikov u krys v khode adaptatsii k vysokogor'iu Antarktidy i posleduiushchei deadaptatsii.

In the experiments performed on 100 white non-inbred male rats (some of them have been kept at the altitude of 3.488 m in the station Vostok, and others--at the coastal level in the station Mirny) testes have been studied, as well as morphometric analysis of convoluted seminiferous tubules and estimation of spermatogenesis activity. During the first month of living at the altitude the section area of the convoluted seminiferous tubules decreases, while the area of their lumen increases. During subsequent periods in the animals, living at the altitude, differences in the parameters, in comparison with the control, disappear. During the first 6 months of their living at the altitude a sharp decrease in spermatogenesis activity is observed. A month of life at the coastal level (after 10 months of hypoxic effect) does not result in normalization of the spermatogenesis activity.

[Features of the capillarization of the skeletal muscles of the white rat during adaptation to high altitude in the Pamir Mountains and the Antarctic]. / Osobennosti kapilliarizatsii skeletnoi myshtsy belykh krys v khode adaptatsii k usloviiam vysokogor'ia Pamira i Antarktidy.

The capillary-myofiber quantitative relations were examined morphometrically in 180 white male rats exposed for 1.5 month to altitudes of 3488-4000 m above sea level (Antarctic and Pamir highlands). During the first three weeks of adaptation drastic changes in the parameter were seen. It is suggested that one of the factors responsible for them is a shift in the functional status of muscles produced by the method of transportation of the animals to the high altitude environment.

[Capillarization of the myocardium of the yak]. / Kapilliarizatsiia miokarda iaka.

Organometric and histometric characteristics of various parts of the heart have been performed in the yak, a permanent inhabitant at altitudes of 3,000-5,000 m above the sea level. Forty hearts of mature animals have been studied. Morphometric investigations of capillaries in the muscle fibers have been carried out in the atrial walls, in the right and left auriculae. in the ventricles and in the papillary muscles. The data are presented for each cardiac part: they describe diameters, density and volume of the capillary network and muscle fibers. In order to estimate the degree of capillarization of the cardiac muscle tissue, a new parameter is suggested to be used, when analyzing the morphometric data. It characterizes ratio of capillaries volume. According to the criterion given, a significant difference is stated between the degree of capillarization in the myocardium of the right and left ventricles. We suppose that this adequately reflects an increased loading experienced by the right cardiac parts under a long-lasting effect of altitude factors.