Oxidant-induced arachidonic acid release and impairment of fatty acid acylation in vascular smooth muscle cells

Oxidative damage, which plays a major role in the early stages of atherosclerosis, is associated with arachidonic acid (AA) release in vascular smooth muscle cells (VSMC) as in other cell types. In this study, H2O2was used to investigate mechanisms of AA release from VSMC on oxidative stress. Cell treatment with H2O2inhibited AA incorporation in an inverse relationship to prolonged H2O2-induced AA release. Identical kinetics of inhibition of AA incorporation and AA release were observed after cell treatment with A lF 4 − , a process not involving phospholipase A2(PLA2) activation as recently described (A. Cane, M. Breton, G. Bereziat, and O. Colard.Biochem. Pharmacol. 53: 327–337, 1997). AA release was not specific, since oleic acid also increased in the extracellular medium of cells treated with H2O2or A lF 4 − as measured by gas chromatography-mass spectrometry. In contrast, AA and oleic acid cell content decreased after cell treatment. Oleoyl and arachidonoyl acyl-CoA synthases and acyltransferases, as...