The reproductive system of male rats exposed to very low doses of ionizing radiation, 1: Hormonal profile of animals exposed after sexual maturity

Adult male rats were treated with a single, whole body exposure to a dose of 0.001, 0.01 or 0.1 Gy (1 Gy = 100 rad). The animals were sacrificed 1, 7, 30, 100 or 180 days following exposure. Serum testosterone, serum and hypophyseal LH, FSH and prolactin as well as hypothalamic LHRH were measured. In the 0.1 Gy irradiated rats, serum LH and FSH were 100% higher and serum prolactin was 30% lower as compared to controls, 30 days after irradiation. The concentrations of these hormones remained significantly different from control values even after 180 days after exposure. On the other hand, the hypophyseal content of LH, FSH and prolactin decreased in the 0.1 Gy treated rats, 100 days after irradiation. In the group of the 0.01 Gy irradiated rats, serum FSH increased by 70% and hypophyseal FSH decreased. No changes were observed in serum testosterone and hypothalamic LHRH in any of the irradiated groups and no changes were observed in the group exposed to 0.001 Gy. It may be concluded that a long term damage to the reproductive system of the male rat was induced by a single, whole body exposure to 0.1 Gy of gamma radiation.