HYPOTHALAMIC-PITUITARY-TESTICULAR SYSTEM FOLLOWING TESTICULAR X-IRRADIATION

Abstract

Testes of adult, male rats were exposed to a total dose of 1500 R of X-irradiation. Testicular weight decreased from day 8 after X-ray treatment. This decrease was preceded by an increment of the testis weight on day 4 following treatment. X-ray treatment of testes was associated with significant increases in serum FSH [follicle stimulating hormone]. Testicular irradiation had no effect on ventral prostate and seminal vesicles weights. Serum testosterone increased only on day 1, 2 and 4 after irradiation, while serum LH [luteinizing hormone] levels tended to increase from day 8 post-irradiation. These changes were not significant when compared with non-irradiated controls. At 7, 13 and 20 days following 1500 R of bilateral, testicular X-irradiation, the hypothalamic-pituitary unit was still capable of responding to exogenous gonadotropin-releasing factor. Serum FSH may in male rats be regulated at least partly by circulating steroids of testicular origin and partly by an unknown factor of non-interstitial cell nature.