Effect of prolactin and bromocriptine on intestinal transit in mice

In vivo administration of relatively high concentrations of prolactin (PRL) enhanced gastrointestinal propulsion in mice. Pretreatment with atropine significantly abolished this effect of PRL while physostigmine enhanced it. The evidence confirms a cholinomimetic action for higher concentrations (20 microgram) of PRL on the intestinal tract. Bromocriptine per se produced a dose-dependent depression in transit while a combination of PRL and bromocriptine failed to significantly alter the transit as compared to the control.