Effects of passive immunization against testosterone on the sexual activity of female rhesus monkeys

Active immunization of an ovariectomized rhesus monkey against testosterone-3(0-carboxymethyl)oxime-bovine serum albumin produced an antiserum with a high degree of specificity towards testosterone. Passive immunization of ovariectomized, oestrogen-treated monkeys with this antiserum resulted in significant reductions in proceptive and/or receptive behaviours in the majority of animals. This effect could be reversed by treatment with 17 alpha-methyltestosterone, a steroid which showed only 6% cross-reaction with the antiserum. Passive immunization caused an increase in the binding of testosterone by the gamma-globulin fraction of serum isolated by treatment with 2-ethoxy-6,9-diaminoacridine lactate. The present findings emphasize the importance of androgens of adrenal origin in the regulation of sexual behaviour in the female rhesus monkey.