Muscarinic Receptors in Chromaffin Cell Cultures Mediate Enhanced Phospholipid Labeling but Not Catecholamine Secretion

The addition of either carbachol or muscarinic agonists to cultured bovine adrenal chromaffin cells results in a selective stimulation of phosphatidate (PhA) and phosphatidylinositol (PhI) labeling from 32 P i and [ 3 H]glycerol that can be inhibited by the inclusion of atropine, but not d -tubocurarine. In contrast, increased catecholamine secretion is observed on the addition of carbachol or nicotinic agonists and is inhibited by d -tubocurarine but not by atropine. Added calcium is essential for catecholamine secretion but not for stimulated phospholipid labeling. Chelation of endogenous Ca 2+ with EGTA does, however, inhibit the stimulated phospholipid labeling. These results suggest that stimulated phospholipid labeling in the bovine chromaffin cell and catecholamine secretion are separate and distinct processes.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65292/1/j.1471-4159.1981.tb00482.x.pd