title: Effects of progesterone on the sexual behavior of castrated, testosterone-treated male cynomolgus monkeys (Macaca fascicularis).
abstract: In male cynomolgus monkeys the synthetic progestin, medroxyprogesterone acetate (MPA), decreases testosterone (T) levels and sexual behavior, binds to progestin receptors in brain, and reduces by about 70% the uptake of [3H]androgens by both brain and genital tract tissues. To examine the behavioral effects of progesterone (P) itself, eight castrated, T-treated males were each tested twice weekly with an estrogenized female before, during, and after they were treated with two SC Silastic P implants. Data from six 4-week treatment periods were analyzed to facilitate comparisons with our previous data using MPA: i) baseline, ii) weeks 4-7 of P treatment, iii) weeks 8-11 of P treatment, iv) weeks 1-4 after P implants were removed, v) weeks 5-8 after P withdrawal, and finally vi) weeks 9-12 after P withdrawal (384 1 h behavior tests). Weekly blood samples (N = 192) were analyzed by radioimmunoassay to determine plasma levels of both T and P. P treatment, which resulted in high plasma P levels (about 44 ng/ml), produced decrements in measures of male sexual behavior and motivation that were both qualitatively and quantitatively similar to those produced by MPA treatment but, unlike MPA, P did not decrease plasma T levels or change them in any way (about 850 ng/100 ml throughout). The findings suggest that P implants may be preferable to weekly MPA injections in the treatment of male sex offenders because they require less patient compliance and may not have MPA's troubling side effects.
authors.affiliation: Department of Psychiatry and Behavioral Sciences, Emory University School of Medicine, Atlanta, Georgia 30322, USA.
authors.forename: D
authors.initials: D
authors.lastname: Zumpe
authors.forename: A N
authors.initials: AN
authors.lastname: Clancy
authors.forename: R P
authors.initials: RP
authors.lastname: Michael
mesh_terms: D000818:Animals; D001921:Brain / Q000187:drug effects; D003307:Copulation / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004343:Drug Implants; D004542:Ejaculation / Q000187:drug effects; D005260:Female; D008252:Macaca fascicularis; D008297:Male; D017258:Medroxyprogesterone Acetate / Q000494:pharmacology*; D009919:Orchiectomy; D011374:Progesterone / Q000494:pharmacology*; D045167:Progesterone Congeners / Q000494:pharmacology*; D011980:Receptors, Progesterone / Q000187:drug effects; D012726:Sexual Behavior, Animal / Q000187:drug effects*; D013739:Testosterone / Q000097:blood / Q000494:pharmacology*
chemical_list: D004343:Drug Implants; D045167:Progesterone Congeners; D011980:Receptors, Progesterone; D013739:Testosterone; D011374:Progesterone; D017258:Medroxyprogesterone Acetate