Structural changes in myocardium of rats with experimental hypothyroidism

The purpose of the study. The study of structural changes in the myocardium in experimental model of hypothyroidism. Materials and methods. The work was performed on experimental data. Experimental model of hypothyroidism in 66 white male rats by means of an operation of thyroidectomy. Duration of experience 45 days. In the postoperative period, rats were removed from the experiment after 5, 7, 21, 28, 35 and 45 days. The control group consisted of 22 rats thyroidectomy was carried out. For histological examination took pieces of myocardium were fixed in 10 per cent buffered formalin, prepared for histological sections via standard methods. The sections were stained with hematoxylin and eosin, pikrofuksin by van Gieson, Mallory, by toluidine blue, elective painting on fibrin, spent the pas reaction. Immunological study was conducted peroxidase-antiperoxidase method using markers desmin, myogenin and sarcomere actin. Results. Microscopic examination of the myocardium are observed hemodynamic disorders: hyperemia of the vessels, eritrociti, erythro-and leukodepleted, and interstitial edema. Marked degenerative changes of cardiomyocytes breach of contracture of myofibrils, focal lymphocytic infiltrates, areas of plasmolysis and fragmentation of fibers. In the stroma of the myocardium is observed mucous swelling with the formation of cavities. Immunohistochemical study showed a reduction in positive expression of desmin from 3 points to 1 points, the decrease in the expression myogenin with a 3 to 1 score, decrease of expression of sarcomere actin from 3 to 1 points. By the end of the experiment at the 45 th day on the background subpositions the expression of these markers there are areas of negative expression. Conclusion. In the simulation of hypothyroidism in laboratory animals develop pronounced structural changes, which are characterized by vascular disorders, diffuse edema of the stroma, dystrophic and destructive changes of cardiomyocytes according to the type of miotsitolizom, colliquation necrosis, fragmentation of the fibers, formation of focal lymphocytic infiltrates and sclerotic processes by the end of the experiment. Immunohistochemical study observed a decrease in the expression of desmin, sarcomere actin and myogenin.

hypothyroidism, myocardium, cardiomyocytes, degeneration, plasmolysis, desmin, myogenin, actin sarcomeres

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