[Morphologic characteristics of the hearts of argali continuously dwelling at high mountain altitudes].

The hearts of argali living at 3800-5000 m above the sea level were examined. Macroscopy showed complete absence of fatty tissue under the epicardium. Increased number of the capillaries surrounding cardiomyocytes, intercalated discs in many zones of the myocardium, sharp thickening giving pronounced cross lines of myofibrils were revealed on semithin and ultrathin sections. The data obtained demonstrate specificity of the heart structure of argali and are discussed from the standpoint of increased compensatory-adaptive changes in the test organ, these changes being associated with its enhanced function provoked by high altitude conditions.