Effect of Antigonadotropic Sera on In Vitro Testicular Metabolism of³H-Testosterone in Immature Rats

Male rats were daily injected from the 5th day to the 21st day of life with purified rabbit anti-FSH serum, or anti-LH serum. After the last injection, they were killed and the testes incubated in vitro with 3H-testosterone. The radioactive metabolites were separated and identified by a double isotope dilution method. In rats treated with antigonadotropic sera, the total amount of 5 alpha-reduced metabolites was significantly decreased. The profile of the 5 alpha-reduced metabolites obtained in the anti-FSH treated group was different from those obtained in control and anti-LH treated groups. Antigonadotropic sera modify the in vitro metabolism of testosterone by the testicular tissue.