Heterogeneity of the thymus epitheliocytes and their ultrastructure in newborn rats with disturbed balance of glucocorticoids [Geterogennost' épiteliotsitov timusa i ikh ul'trastruktura u novorozhdennykh krys pri disbalanse gliukokortikoidov.]

Four types of epitheliocytes were identified in thymus of intact newborn rats by ultrastructural features and using the data from the literature. In progeny of female rats receiving injections of hydrocortisone acetate, dark cells (type IV) were prevalent. Signs of epitheliocyte hypertrophy and intensification of intracellular differentiation were noted: thickening of tonfilaments bundles and enlargement of vacuoles with electron dense amorphous contents, in type I epitheliocytes, increase of number and size of cluster vacuoles in type II epitheliocytes, signs of epitheliocyte destruction along with their hypertrophy were detected in the thymus type I epitheliocytes of the progeny following adrenalectomy of prynant females. The changes demonstrated are thought to be due to increase of corticosteroid content in the developing organism.