[Myocardial damage during immobilization stress and the protective effect of thyroid hormones].
In the experiments performed on 30 white inbred male rats, the stress produces an essential increase of dilated canals in the T-system and sarcoplasmic reticulum, lesions of sarcolemma and nucleolemma, fragmentation and homogenization of mitochondrial cristae; there are many pinocytic vesicles in the capillary walls. Preliminary injection of thyroid hormones in small doses, that do not result in any noticeable influence on the body mass, cardiac contraction rate and thyrotoxin concentration in blood serum, at the stress causes less pronounced changes in ultrastructure of cardiomyocytes, demonstrating as a poor swelling of the T-system elements, preservation of the sarcolemmic integrity at its larger length; besides, large mitochondria with compact arrangement of cristae appear, amount of the sarcoplasmic reticulum elements increases, chromatin margination becomes evident, i. e. a complex of adaptive processes develops. The data presented demonstrate a defensive role of physiological concentrations of the thyroid hormones under the stress.
D000818:Animals; D009202:Cardiomyopathies / Q000209:etiology* / Q000473:pathology / Q000517:prevention & control; D008297:Male; D008854:Microscopy, Electron; D009206:Myocardium / Q000648:ultrastructure*; D009940:Organoids / Q000648:ultrastructure; D051381:Rats; D012149:Restraint, Physical; D013312:Stress, Physiological / Q000150:complications* / Q000188:drug therapy; D013963:Thyroid Hormones / Q000627:therapeutic use*
D013963:Thyroid Hormones; C004227:thyroidin
Povrezhdenie miokarda pri immobilizatsionnom stresse i zashchitnyĭ éffeckt tireoidnykh gormonov.