Luteinizing hormone secretion is enhanced by pertussis toxin, cholera toxin, and forskolin. Evidence for the involvement of the cyclic AMP-generating system.

Pertussis toxin, cholera toxin and forskolin, all of which can increase adenylate cyclase activity, stimulated luteinizing hormone LH release from cultured rat anterior pituitary cells. Although cellular cyclic AMP and growth hormone were increased rapidly by cholera toxin and forskolin, enhanced LH release occurred significantly later with no change in total radioimmunoassayable LH (i.e., released plus stored). These data suggest that changes in cyclic AMP levels may regulate the tonic availability of releasable LH in the gonadotroph.