Evidence for receptor-linked activation of phospholipase D in rat parotid glands Stimulation by carbamylcholine, PMA and calcium

• Published in: FEBS letters Vol. 314; no. 3; pp. 489 - 492
• Main Authors: Guillemain, Isabelle, Rossignol, Bernard
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 21-12-1992; Elsevier
• Subjects: 4β-phorbol 12-myristate 13-acetate; acetylcholine; activation; Analytical, structural and metabolic biochemistry; Animals; Biological and medical sciences; Calcium; Chromatography, Thin Layer; Enzyme Activation; Enzymes and enzyme inhibitors; Fundamental and applied biological sciences. Psychology; Hydrolases; Ionophores - pharmacology; Kinetics; Male; muscarinic; Parotid acini; parotid gland; Parotid Gland - enzymology; PEth; phosphatidic acid; phosphatidylethanol; phospholipase D; Phospholipase D - metabolism; Phospholipase D: Muscarinic receptor. Phorbol ester; PKC; PLD; PMA; protein kinase C; Rats; Rats, Sprague-Dawley; receptors; Receptors, Muscarinic - metabolism; Signal Transduction; Tetradecanoylphorbol Acetate - pharmacology; PA; Calcium; PMA; PLD; PKC; Phospholipase D: Muscarinic receptor. Phorbol ester; PEth; Parotid acini; Vertebrata; Mammalia; Enzymatic activity; Parotid gland; Rat; Enzyme; Rodentia; Muscarinic receptor; Phospholipase D
• ISSN: 0014-5793; 1873-3468
• DOI: 10.1016/0014-5793(92)81533-R

In order to test if phospholipase D (PLD) activity exists in the rat parotid gland, we took advantage of the fact that, in the presence of ethanol, PLD generates phosphatidylethanol (PEth) via a transphosphatidylation reaction. Lipid extracts of parotid acini prelabelled with [
3H]myristic acid were analyzed by thin layer chromatography to determine [
3H]phosphatidylethanol ([
3H]PEth) formation. Carbamylcholine (1 mM) stimulated [
3H]PEth formation in the presence of 2% ethanol, this effect was completely inhibited by atropine (10 μM), PMA (0.1–1 μM) and ionomycine (10 μM) also caused [
3H]PEth generation. We conclude that a phospholipase D activity is present in the rat parotid gland and is regulated by muscarinic cholinergic receptors. Protein kinase C and calcium could also modulate this activity. This report provides the first evidence for the existence and receptor-linked regulation of phospholipase D in an exocrine gland, the rat parotid gland.