Induction of sexual behavior in ovariectomized rhesus females with 19-hydroxytestosterone

Abstract

Eight sexually experienced long-term ovariectomized female rhesus monkeys were given tests of sexual behavior following treatment with 19-hydroxytestosterone (19-OH-T, 1 mg/day for 13 days), and their performance was compared with that following treatment with estradiol benzoate (EB, 10 μg/day for 13 days). Each female was tested for 10 min with each of nine adult males. Blood samples were taken on the last day of treatment with EB, at the end of the intervening 3-month period of no treatment, and on the last day of treatment with 19-OH-T. Blood levels of testosterone and estradiol were quantified by radioimmunoassay. Mean rate of presenting at a distance (proceptive behavior) was significantly higher ( P < 0.05) when they were treated with 19-OH-T, but the ratio of presents to male contacts (receptive behavior) was significantly higher ( P <0.05) when they were treated with EB. All other components of female sexual behavior were the same. Males displayed fewer annoyance responses (rejecting jerk, P < 0.05) when the females were treated with 19-OH-T than when they were treated with EB. All other male responses occurred with the same frequencies under the two female treatment conditions. Injection of 19-OH-T and EB both resulted in plasma testosterone and estradiol levels higher than those found in the untreated condition. Testosterone levels did not differ under the two treatments ( P > 0.05), but estradiol levels were higher under EB treatment than under 19-OH-T ( P < 0.05). This study suggests that both testosterone and estradiol are essential for maximum sexual performance and that various components of sexual behavior may be differentially influenced by the ratio of testosterone to estradiol in plasma.