PERIODIC USE OF CABERGOLINE, A PROLACTIN INHIBITOR, FOR CONTROL OF REPRODUCTIVE SUCCESS IN RATS - WORK-IN-PROGRESS

Cabergoline is a patent prolactin inhibitor which stimulates dopaminer gic receptors, acting as a prolactin-inhibiting-factor (PIF) agonist. Pairs of mature and fertile Wistar rats were fed 3 doses of cabergolin e in an oily vehicle (treatment, n=5 each), or the vehicle only (contr ol, n=10) as a top dressing on feed, given once or twice weekly for 9 wk, followed by a 6-wk recovery period. Reproductive success was evalu ated by counting pregnancies resulting in delivery and pups born alive or dead over the 15-wk period. Groups of 5 pairs each responded to tr eatment with 100 or 150 mu g cabergoline fed once weekly, or 50 mu g t wice weekly, with reduction or prevention of reproductive success. Pre gnancies either did not go to term, or the pups were stillborn or died within 12 h of birth (P<0.001). Treatment with 50 mu g cabergoline on ce a week: was only partially effective (P>0.05). Rats in the control group experienced unimpaired reproductive success. No carry-over effec ts on pup survival into the recovery period were observed; reproductiv e success was restored within 2 to 3 wk. Treatment with cabergoline di d not affect body weight, the estrus cycles or the mating frequency. N o aversion to cabergoline was observed over time.