[A study on the regulation of ACTH secretion in rat pituitary cells]

In addition to method of ACTH RIA, a rat pituitary cell perfusion system was developed for the assessment of pituitary cells in stimulating and inhibiting ACTH secretion induced by some substances. Hypothalamic extract stimulated the ACTH secretion in a dose-dependent manner. AVP, cAMP, Ca2+, K+, noradrenaline, metoclopramide and haloperidol also had some stimulating effect. Dexamethasone and dopamine inhibited the basal ACTH secretion of pituitary cell and antagonized the effect of the various stimulating substances. Cyproheptadine could antagonize the effect of some of the stimulating substances while GABA had no marked inhibiting effect.