Effect of the induction of moderate hyperprolactiniemia on sexual behavior in wistar male rats

At physiological high levels, Prolactin (PRL) is related with many functions, including lactation, reproduction and sexual behavior. Abnormal high levels, referred to as hyperprolactinemia (HP), are associated with sexual disorders like hypogonadism, erectile dysfunction and infertility. Male rats with HP display less mounts and intromissions, as well as higher ejaculation latencies, however, little is known about the effect of modest HP. To learn more about this topic, the study aims to analyze the effect of a moderate HP (40 ng/ml), induced by pituitary transplantation and ovine PRL administration (100μg/d), on sexual behavior of sexually experienced male rats. Sixty-four sexually experienced male rats were randomly assigned to 4 groups: 1) Ctrl; 2) oPRL; 3) Graft and; 4) Sham. During a time of 15 days, rats were subjected to a sexual behavior test every three days. The last day, sexual behavior was tested with the SBR Software. Results showed that pituitary graft produced and increase in the number of mounts, and longer intromission-ejaculation latencies compared with controls. Also, we found that hit rate was reduced. Interestingly, these parameters are related with the anticipatory/consummatory phases of the sexual behavior, suggesting a role of PRL in males with not chronic HP.