[Effect of heparin on the thyroid gland]

Effect of heparin on the white rat thyroid gland has been studied in vivo and in vitro by means of light microscopy, electron microscopy and radiometry methods. Heparin is injected subcutaneously (1,000 units per 100 g of the body mass) once in 24 h. In the in vitro experiments heparin contents in medium is 10 units/ml and 10 units/ml. Heparin produces a decrease in thyrocyte height (control--12.6 +/- 0,5, experiment--10.4 +/- 0.6 mcm), a decrease in the number of folds on the basal surface of thyrocytes, changes in Golgi complex and an increase in electron density of the mitochondrial matrix. In endotheliocytes of the perifollicular blood capillaries the number of fenestrae decreases. Iodine accumulation in the thyroid is lowered under the effect of heparin. The thyroid gland blood stream (estimated by accumulation of 86Rb) decreases by 35%. The data obtained support the previous suggestion of the authors on a system-forming role of the tissue basophils in the thyroid micro-region.