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 32Pi and [3H]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 Ca2+ 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.
D000313:Adrenal Medulla / Q000378:metabolism*; D000818:Animals; D001285:Atropine / Q000494:pharmacology; D002118:Calcium / Q000494:pharmacology; D002395:Catecholamines / Q000378:metabolism*; D002417:Cattle; D002838:Chromaffin System / Q000378:metabolism*; D007700:Kinetics; D010710:Phosphates / Q000378:metabolism; D010743:Phospholipids / Q000378:metabolism*; D010761:Phosphorus Radioisotopes; D011950:Receptors, Cholinergic / Q000187:drug effects / Q000378:metabolism*; D014316:Tritium; D014403:Tubocurarine / Q000494:pharmacology
D002395:Catecholamines; D010710:Phosphates; D010743:Phospholipids; D010761:Phosphorus Radioisotopes; D011950:Receptors, Cholinergic; D014316:Tritium; D001285:Atropine; D002118:Calcium; D014403:Tubocurarine