[The influence of hormones on behavior]

The effect of cyproterone acetate on motor activity, aggression, "emotionality", body weight and testes in wild mice

The literature reports on antiandrogenic and antigonadotropic effects of cyproterone acetate (CA) and on its inhibitory influence on the structure and function of the testis and reduction of the sexual drive in man and animals. No one has as yet been able to confirm a reduction of aggression which could be expected under CA. Isolated male wild mice received daily doses of 0.5 mg (17 mg/kg) CA subcutaneously over 32 days and were studied daily for aggressive behavior, motor activity and emotionality during the last 11 days. Aggression was reduced significantly by CA in the form of an increased latent time and continued to decrease during the test period with a reduction of fighting time and the correlated coarse motor activity. A latent period of approximately 4 weeks was determined for the aggression-inhibiting effect of CA. The detection rate was not changed under CA. It is doubted whether it is an adequate parameter of "emotionality". The overall motor activity was not reduced, so that an aggression-specific effect is assumed rather than a general reduction of drive. The body and testicular weight was reduced, the testicular tissue atrophies. Central points of attack of CA probably play a major role in the reduction of aggression.