A comparison of the effects of CB-154 and lergotrile mesylate on prolactin and growth hormone secretion in mice.

The influence of 2-bromo-alpha-ergocryptine (CB-154) and 2-chloro-6-methyl-ergoline-8beta-acetonitrile methanesulfonate (lergotrile mesylate) on prolactin (PRL) and growth hormone (GH) secretion in mice was investigated. Both drugs inhibited the nursing-induced rise in serum PRL in lactating mice, CB-154 being effective at a somewhat lower dosage than lergotrile mesylate. Both drugs reduced basal concentrations of serum PRL by more than 90% within an hr after administration, but the effect of CB-154 lasted for several hr longer than that of lergotrile mesylate. CB-154 did not change the resting concentrations of GH in mice, but it promoted the induction of GH release by nursing; injection of lergotrile mesylate, on the other hand, seemed to enhance the basal concentrations of GH in lactating mice that were separated from their young for 12 hr. The results show that both drugs can be used successfully for reducing PRL secretion in the mouse.