Effect of treatment with different doses of bromocriptine on plasma profiles of prolactin, gonadotrophins and testosterone in mature male rats and mice.

Abstract

The influence of different doses of bromocriptine (CB-154) on plasma levels of prolactin (Prl), FSH, LH and testosterone (T) in mature male rats and mice was studied. Daily subcutaneous administration of 360 micrograms of CB-154 in sesame oil was sufficient to induce maximal suppression of plasma Prl levels in mature male rats whilst subcutaneous implantation of two pellets of CB-154 and cholesterol, each containing approximately 6 mg CB-154, was effective in suppressing serum Prl levels in mature rats for at least four weeks. This was accompanied by a significant elevation of plasma levels of LH and FSH. A similar dose-response study in mature male mice suggested that relatively higher doses of CB-154 are required to suppress plasma levels of Prl in this species, although large doses of CB-154 can still increase plasma levels of gonadotrophins and T in male mice.