Sexual Activity and Urinary Steroids in Man with special reference to Male Homosexuality

Abstract

In his Upjohn lecture Professor G. W. Harris (1964) reviewed experiments on the effects of gonadal hormones on the sexual behaviour of animals. He compared sexual behaviour patterns of male rats castrated on the first day of life with those of adult castrates. When fully grown, these day-old castrates were either primed with oestrogen and progesterone and tested for female mating behaviour, or they were given testosterone and tested for male behaviour with receptive females. Thus, Harris was able to demonstrate bisexual behaviour (mediated through hypothalamic-pituitary pathways) with female type activity cycles occurring in male rats. These experiments suggest that gonadal hormones exert a dual effect. During the early phase of development they act inductively, and later in the adult they exert an excitatory action on the central nervous system.