Effects of various secretagogues on gonadotropin release by rat anterior pituitary cell cultures.

Rat anterior pituitary cell cultures were utilized to compare LH and FSH release induced by LHRH, cAMP derivatives, cGMP derivatives, the calcium ionophore A23187, and elevated K+. Of the cyclic nucleotide derivatives tested, only 8-Br-cAMP released significant quantities of both LH and FSH. A23187 and elevated K+ released significant quantities of LH and FSH but supramaximal concentrations of these stimuli liberated only approximately 50% of the gonadotropins released by LHRH. Thus, none of the secretagogues tested was as efficacious as LHRH in releasing either LH or FSH.