Abstract
We reinvestigated the involvement of the nicotinic-acetylcholine receptor in catecholamine secretion from chick adrenal chromaffin cells. Nicotine (10-8-10-4M), as well as methacholine, caused a dose-dependent increase in the cytosolic concentration of Ca2+ and catecholamine secretion from freshly isolated adrenal chromaffin cells. The effects of acetylcholine (10-4M) were effectively inhibited by both hexamethonium (10-4M) and atropine (10-5M), and almost completely blocked by both antagonists. The results suggest the existence of functional nicotinic receptors, which mediate Ca2+ mobilization and catecholamine secretion, in chromaffin cells of chick adrenal glands.
