Description
An experiment was performed to determine if hyperprolactinemia (chronically elevated serum prolactin levels), which inhibits testosterone-activated male sexual activity, also affects other androgen-dependent behaviors. Thus defecation and urine marking in response to a novel environment were examined in sham-operated and pituitary-grafted (hyperprolactinemic) male rats that had been castrated or castrated and given subcutaneous testosterone implants. Both castration and pituitary grafting significantly inhibited defecation, with the inhibitory effects of hyperprolactinemia being most pronounced in the castrated non-testosterone-treated animals. In contrast, castration significantly reduced the amount of urine marking observed, but pituitary grafting was without effect on this behavior. Thus, although hyperprolactinemia may inhibit sexual activity through an antagonism of the activational effects of testosterone, these results suggest that this effect is specific to sexual behavior and does not involve a more generalized inhibition of the effects of testosterone on androgen-dependent behaviors.
Subject
Animal/*physiology; Animals; Arousal/physiology; Brain/*physiology; Defecation/physiology; Inbred F344; Male; Mesencephalon/physiology; Neural Inhibition/*physiology; Neural Pathways/physiology; Preoptic Area/physiology; Prolactin/*physiology; Rats; Sex Attractants/*urine; Sexual Behavior; Testosterone/*physiology; Urination/*physiology