Behavioral responses to ovariectomy and chronic anabolic steroid treatmentin female cynomolgus macaques

A pilot study was conducted to investigate the effects of ovariectomy on ra tes of aggressive and affiliative behavior, as well as body size, in 38 you ng adult female cynomolgus monkeys (Macaca fascicularis) living in isosexua l social groups of four to five animals. In addition, we assessed the effec ts of nandrolone decanoate tan anabolic steroid used for postmenopausal hor mone replacement therapy) on indices of aggression, submission, and body si ze. Animals were randomized into three experimental conditions: 1) sham ova riectomized, untreated (SHAM); 2) ovariectomized, untreated (OVX); and, 3) ovariectomized, treated with nandrolone decanoate for 24 months (NAN). Each individual was observed for 10 min, one to two times per month, and all in stances of agonistic and affiliative behavior were recorded by means of foc al animal sampling. Ovariectomized, untreated animals exhibited a two- to t hreefold increase in aggression compared to SHAM or NAN animals; F(2, 32) = 4.09, p = 0.026; however, the expression of prosocial or affiliative behav iors as measured by rates of grooming and initiating friendly behavior was unaffected. At an i.m. dose of 25 mg every 2 weeks, nandrolone decanoate ca used a 60% increase in body weight of the animals compared to untreated int act and ovariectomized animals, F(2, 31) = 161.57, p < 0.0001. (C) 1999 Els evier Science Inc.