PATHOHISTOLOGICAL CHANGES IN THE MYOCARDIUM OF RATS UNDER THE ACTION OF GENERAL HYPOTHERMIA IN THE LATE PERIOD

Belimenko M. S., Kosharniy V. V., Abdul-Ogly L. V., Kozlovskaya O. G., Kushnaryova K. A.

PATHOMORPHOLOGY

Scentific article

Abstract. At present, immunohistochemical research methods are widely used in the study of histogenetic pro- cesses of morphogenesis, due to their high sensitivity and informativeness. Hypothermia is a situation in which the internal body temperature drops below 35 degrees Celsius. The article presents the relevance, theoretical aspects and features of the action of general hypothermia on the heart in general and cardiomyocytes in particular. The aim of the study was to establish changes in the myocardium under the action of general hypothermia at the histological and immunohistochemical level at a later date. Materials and methods. The subjects of the study were the hearts of laboratory adult rats. The study involved 54 animals. Our study found uneven accumulation of endothelial dysfunction marker e NOS and LC3B autophagy with the highest degree of expression of these markers in rat myocardial vascular endotheliocytes after exposure to general late-onset hypothermia with a 30-day-long negative duration of the experiment. general hypothermia on the vessels of the microcirculatory tract. After hypothermia in the myocardium there are destructive changes with the develop- ment of interstitial fibrosis and increased degenerative and destructive processes in the myocardium of the heart, muscle fiber ruptures, indicating the inhibitory effect and irreversible damage of this type of hypothermia on the heart myocardium. during hypothermia of 30 days there is a hypertrophy of a myocardium of ventricles of heart which is a consequence of development of fibrosis and hypostasis of elements of interstitial spaces that we very clearly observed at histologic level. Conclusions. Increase in weight of heart, change of its form is caused by changes right ventricles. The main trend of changes in the heart wall, especially the myocardium, was vasodilation and a marked increase in the expression of the marker eNOS. The effect of prolonged hypothermia in the myocardium of rats was manifested in the formation of changes in the thickness of the heart wall in the direction of thickening and enhancing the activity of autophagy, which manifested itself in the accumulation of autophagy marker LC3B, which is an indicator of trophic processes and cell death. Hypothermia in the late period, after 30 days of exposure. After hypothermia in the myocardium there are destructive changes with the development of interstitial fibrosis and increased degenerative and destructive processes in the myocardium, sometimes ruptures of muscle fibers, which indicates the inhibitory effect and irreversible damage of this type of hypothermia to the myocardium.

myocardium, hypothermia, immunohistochemical.

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«Bulletin of problems biology and medicine» Issue 2 (160), 2021 year, 253-257 pages, index UDK 616.12:616-001.8:616.127-092.4

10.29254/2077-4214-2021-2-160-253-257