Effects of bromocriptine (CB-154) treatment on copulatory behavior in hyperprolactinemic adult male rats

Adult male rats received pituitary transplantations to induce hyperprolactinemia. Some of those had bromocriptine (CB-154) treatment, and the other had vehicle (saline) as control. The grafted animals with vehicle exhibited significantly more suppression than sham operated animals. While the hyperprolactinemic rats treated with CB-154 showed no significantly more suppression of copulatory behavior than sham operated control. In the grafted animal without CB-154 treatment, the concentration of serum PRL was significantly higher than in sham operated controls. There were no significant differences in adrenal weight and serum levels of gonadotropin between grafted and control groups. These results may imply that PRL has direct actions on central nervous system (CNS) and inhibits copulatory behavior in hyperprolactinemic male rats.