Magnesium Antagonizes the Actions of Lysophosphatidyl Choline (LPC) in Myocardial Cells
- 1 June 1995
- journal article
- cardiovascular anesthesia
- Published by Ovid Technologies (Wolters Kluwer Health) in Anesthesia & Analgesia
- Vol. 80 (6), 1083-1087
- https://doi.org/10.1097/00000539-199506000-00003
Abstract
Patients with cardiac arrhythmias, ischemia, and infarction may benefit from administration of supplemental magnesium.However, the exact mechanisms for magnesium's beneficial effects remain unknown. Lysophosphatidyl choline (LPC), an amphipathic phospholipid released from cardiac cell membranes during ischemia, increases free intracellular calcium concentrations ([Ca]i) and has been implicated as a cause of cardiac arrhythmias and coronary artery spasm during myocardial ischemia. We postulated that magnesium acts by inhibiting cellular calcium overload induced by mediators such as LPC. Myocardial cells from male Sprague-Dawley rats were isolated from ventricular tissue samples and [Ca]i determined using the fluorescent dye, fura-2/acetoxymethyl ester, measured in a spectrofluorometer. The increase in [Ca]i after exposure to 100 and 200 micro Meter LPC was recorded in cells suspended in modified Dulbecco's phosphate buffered saline solution with 0.2, 2.0, and 20 mM magnesium chloride. Differences were determined by analysis of variance with P < 0.05 considered significant. LPC significantly increased [Ca]i in the 100 micro Meter (506 +/- 76 nM) and 200 micro Meter (675 +/- 81 nM) concentrations, compared to baseline (301 +/- 25 nM). MgCl2 at both the 2.0 and 20 mM concentrations significantly blunted the increase in [Ca]i in myocardial cells exposed to LPC, whereas 0.2 mM MgCl2 was ineffective. LPC is a potent lipid mediator which increases myocyte [Ca]i in a concentration-dependent manner. Magnesium concentrations >or=to2.0 mM effectively antagonize the increase in [Ca]i induced by LPC. Thus, magnesium may limit intracellular calcium overload stimulated by ischemic-induced LPC release. (Anesth Analg 1995;80:1083-7)Keywords
This publication has 19 references indexed in Scilit:
- Magnesium Inhibits the Hypertensive but Not the Cardiotonic Actions of Low-dose EpinephrineAnesthesiology, 1991
- MAGNESIUM REDUCES INCIDENCE OF POSTOPERATIVE DYSRHYTHMIAS IN PATIENTS AFTER CARDIAC SURGERYAnesthesiology, 1989
- Plasma volume expansion increases lysophosphatidylcholine and digitalis-like activity in rat plasmaLife Sciences, 1988
- Magnesium infusion reduces the incidence of arrhythmias in acute myocardial infarction. A double-blind placebo-controlled studyClinical Cardiology, 1987
- Electrophysiologic effects of intracellular lysophosphoglycerides and their accumulation in cardiac lymph with myocardial ischemia in dogs.JCI Insight, 1986
- INTRAVENOUS MAGNESIUM IN ACUTE MYOCARDIAL INFARCTIONThe Lancet, 1986
- The Use of Magnesium Sulfate in the Anesthetic Management of PheochromocytomaAnesthesiology, 1985
- Magnesium, Electrolyte Transport and Coronary Vascular ToneDrugs, 1984
- Biochemical correlates of airway hyperreactivity in guinea pigs: role of lysophosphatidyl cholineJournal of Allergy and Clinical Immunology, 1983
- Augmentation of cyclic AMP content induced by lysophosphatidyl choline in rabbit heartsCardiovascular Research, 1979