Endocrine changes after hemiadrenalectomy and total body irradiation in parabiotic rats.

Abstract

Abstract A morphologic study was made of endocrine alterations in parabiotic rats during short intervals post irradiation. Aside from the radiosensitive gonadal tissues, few endocrine gland changes were commonly observed, except after prior hemiadrenalectomy. In protected animals ovarian granulosa cells showed postirradiation hyperplasia. In relatively strained adrenal functional states, radiation produced a decrease of lipid and free carbonyl groups in the adrenal cortex. Increased incidences of hyperplasias of thymus, bone marrow leukocyte precursors, and testicular interstitial cells indicated that under maximal experimental strain irradiation had reduced adrenal cortical functions. Pancreatic islets, ovarian theca cells, and thyroid also more often became hyperplastic in postirradiation hypoadrenal conditions. A considerable normal adrenal margin of safety was evident. Pituitary cells showed slight direct radiation effects, after 1,600 r. Anterior pituitary functions seemed unaffected or stimulated post irradiation, as shown by tissue responses attributed to gonadotropin, adrenocorticotropin, growth hormone, and thyrotropin secretion. Cell counts indicated irregular postirradiation hyperplasias of pituitary basophils and eosinophils.