Galactorrhea and bromocryptine treatment in female Macaca fascicularis

Abstract

Five female galactorrhea monkeys in the Primate Lab, Chulalongkorn University were studied. All of them were older than 10 years old and found to have galactorrhea for at least three months before study and were on suspicion of infertility. Four of these monkeys had the histories of pregnancy before. Among these, three out of five displayed regular menstrual cycles. All monkeys had high serum prolactin levels (154-1154 mU/L) and showed low or absence of LH peak. Bromocryptine was administered to those who were hyperprolactinemia - galactorrhea monkeys with the dose of 2.5 mg/day for 30 days. All of them had the prolactin levels returned to normal (109-244 mU/L) within one day. Galactorrhea were disappeared in 4 monkeys within 15 days. The exceptional one was only in reduced amount of milk secretion. Other reproductive hormones, LH, E2 and progesterone were unaffected by this drug. After bromocryptine withdrawal, the recurrences of hyperprolactinemia and galactorrhea were seen in all monkeys within 1 -2 days. The continued treatment of bromocryptine was then presented in 4 monkeys as long for 3 months. During treatment they were mated with fertile male on every mid-cycle periods, no pregnancies could be occurred but the improvement of mating behaviour were seen. It could be concluded from the study that (i) galactorrhea in these monkeys were accompanied by hyperprolactinemia and low LH peak, leading to menstrual disorder and infertility and (ii) bromocryptine suppressed prolactin secretion and stopped galactorrhea but could not improve fertility in aged monkey. Withdrawal of this drug caused prompt recurrence of hyperprolactinemia and galactorrhea.