Reduced arachidonate metabolism in ATP-depleted myocardial cells occurs early in cell injury. Am J Physiol 1990 Aug;259(2 Pt 2):H582-91
Date
08/01/1990Pubmed ID
2117403DOI
10.1152/ajpheart.1990.259.2.H582Scopus ID
2-s2.0-0025025070 (requires institutional sign-in at Scopus site) 23 CitationsAbstract
Exposure of cultured neonatal rat myocardial cells to metabolic inhibitors results in cellular ATP depletion. If prolonged, arachidonic acid is released from membrane phospholipid and irreversible cell injury may ensue. The present study was undertaken to identify the major products of arachidonic acid formed when myocardial cells are depleted of ATP by the metabolic inhibitors 2-deoxy-D-glucose (2-DG) and oligomycin (OG). Under basal conditions, myocardial cells metabolize [3H]arachidonic acid to 6-keto-[3H]prostaglandin (PG)F1 alpha, [3H]PGE2, [3H]PGF2 alpha, 12-[3H]hydroxy-6,8,11,14-eicosatetraenoic acid (12-[3H]HETE) and 11-[3H]HETE, indicating that these cells contain both cyclooxygenase and lipoxygenase pathways. After exposure of myocardial cells to 10 mM 2-DG and 0.1 micrograms/ml OG for 4 h, the basal release of 6-keto-PGF1 alpha and PGE2 is reduced by 3.4-fold and 2-fold, respectively. Supernatants obtained from cells prelabeled with [3H]arachidonic acid and treated with 2-DG and OG for 4 or 12 h did not contain detectable [3H]prostaglandins or [3H]HETEs, but only [3H]arachidonic acid when compared with untreated cells. After 4 and 12 h of treatment with 2-DG and OG, there was a 3.4- and 4.4-fold net release of endogenous arachidonic acid from treated compared with untreated cells. When stimulated with bradykinin, melittin (a phospholipase activator), or arachidonic acid, the synthesis of 6-keto-PGF1 alpha increased to a similar extent in both 2-DG- and OG-treated and -untreated cells. Hence, ATP-depleted myocardial cells do not convert arachidonic acid to oxygenated metabolites under basal conditions. The reduced arachidonic acid metabolism during ATP depletion is not due to direct inactivation of cyclooxygenase or membrane phospholipase. This impairment in arachidonic acid metabolism may represent an early event in myocardial cell injury.
Author List
Revtyak GE, Buja LM, Chien KR, Campbell WBAuthor
William B. Campbell PhD Professor in the Pharmacology and Toxicology department at Medical College of WisconsinMESH terms used to index this publication - Major topics in bold
Adenosine TriphosphateAnimals
Arachidonic Acid
Arachidonic Acids
Cells, Cultured
Deoxyglucose
Myocardium
Oligomycins
Prostaglandins