Effect of Chronic Neutralization of Endogenous FSH on Testicular Function in the Adult Male Bonnet Monkey – Assessment Using Biochemical Parameters

The effect of long‐term passive immunization with a specific homologous antiserum to ovine FSH on testicular function in the adult bonnet monkey was studied. Testicular function was assessed by studying biochemical parameters such as hyaluronidase activity and the rate of incorporation of [³H]thymidine into DNA of testis in vitro. The above parameters were determined in one group of monkeys at 210 days and in another group at 130 days after initiation of antiserum treatment. The testis of both groups of monkeys showed a marked reduction in the rate of [³H]thymidine incorporation into testicular DNA as well as in hyaluronidase activity compared to the corresponding control animals. Further, on withdrawal of antiserum treatment in one set of monkeys, a clear recovery was observed in these parameters, thus demonstrating that the earlier observed effects were specifically due to lack of FSH. The results clearly indicate that chronic lack of FSH affects testicular function in the adult monkey and it is suggested that FSH could have a positive role in spermatogenesis in the adult sub‐human primate.