Effects of long-term immunization against LHRH and androgen treatment on gonadal function.

The possibility of immunological suppression of spermatogenesis while normal libido is maintained by exogenous androgen supplementation was tested in male rats. Neither short- nor long-term treatment with androgen (testosterone-17-trans-4-N-butyl-cyclohexane carboxylate) alone influenced fertility. Active immunization against LHRH administered simultaneously with exogenous androgen supplement caused infertility in 100% of the tested animals, all of which displayed normal sexual behavior. The atrophy of the testes and accessory sex organs was reversible.