The Effects of Ionizing Radiations on Endocrine Cells: I. Steroid Biotransformations and Androgen Production by Testes from Irradiated Mice

Abstract

Methods are presented for the isolation, purifi-cation and characterization of intermediates produced when 5-preg-nenolone-17[alpha]-H3 and progesterone-4-C14 were incubated with mouse testes. It was shown that 17[alpha]-hydroxyprogesterone and androstenedione are important intermediates in the formation of testosterone from these substrates. Total body irradiation of mice with 540 r decreased testicular weight and produced a biphasic response in steroid bio-transformations and androgen production. There was an initial increase in side-chain splitting activity which increased to above normal levels by 30 days post-irradiation. A block in reduction of the oxygen function at carbon-17 was also observed until 20 days post-irradiation. These data were correlated with previously established histologic changes of cellular elements of testes. Pituitary gonadotropins and metabolic cofactors were discussed as possible mediators of the syndrome of effects observed.