Effect of oxygen deprivation on metabolism of arachidonic acid by cultures of rat heart cells

Abstract

To investigate the mechanisms responsible for the impairment of phospholipid metabolism observed in ischemic cells, we have studied the effect of conditions simulating ischemia on the metabolism of arachidonic acid (AA) by muscle (M-) and nonmuscle (F-) cells isolated from newborn rat hearts and cultured separately. In muscle cells, oxygen deprivation induces a significant stimulation of the release of [14C]AA from prelabeled cells associated with a preferential redistribution of [14C]AA into cell triglycerides but not formation of radioactive prostaglandins. Moreover, the fatty acid content of phospholipids, as measured by capillary gas chromatography, appears markedly reduced in ischemic myocardial cells. This fact may be related to phospholipase stimulation during ischemia as suggested by the antagonistic effect of mepacrine or p-bromophenacyl bromide. In contrast, oxygen deprivation failed to induce any significant alteration of AA metabolism in fibroblast-like heart cells. Our results indicate that these cultures of newborn rat heart cells, which exhibit many of the features observed in intact organ during ischemia, may represent a useful experimental model to investigate the pharmacological control of the membrane phospholipid turnover.

Induction of Cytochrome P‐4501A1 Activity in Response to Sublethal Stresses in Microcarrier‐Attached Hep G2 Cells

“…Oxygen deprivation and hydrodynamic shear stress have been shown to increase membrane phsopholipid metabolism (Freyss-Beguin, et al 1989;Nollert et al, 1989Nollert et al, ,1991Bhat and Block, 1992;Michiels et aZ., 1993). In both cases there was a significant increase in prostaglandin synthesis, since the cell models chosen have a disposition for the production of prostaglandins in response to cell stress.…”

Regulation of Arachidonic Acid Release by Calcium Influx in Human Endothelial Cells

“…Radiolabelled fatty acids and phospholipids were extracted by a modified Folch method, separated by thin layer chromatography using Silica Gel 60A plates with a mobile phase of chloroform-methanol and distilled water (65/25/4, v/v), then localized with a Berthold scanner and quantified by liquid scintillation [29]. Analysis of the incubation buffer indicated that 1 95% of the released radioactivity was in the form of free arachidonic acid.…”

Characterization of angiotensin II receptors in cultured adult rat cardiac fibroblasts. Coupling to signaling systems and gene expression.

“…In contrast, in aortic regurgitation or intrarenal aortic stenosis, conditions in which Ang II and aldosterone levels are normal, cardiac hypertrophy is not accompanied by elevated collagen concentrations (25,26). It has been reported that angiotensin converting enzyme inhibitor prevents DNA synthesis in interstitial cells after myocardial infarction and myocardial fibrosis ( 13,27 (29) were used as positive controls for the primary antibodies. The following primary antibodies were tested: a polyclonal antibody against von Willebrand factor (DAKOPATTS, Copenhagen, Denmark) for the detection ofendothelial cells, a monoclonal antibody against sarcomeric tropomyosin (Sigma Immunochemicals) for cardiomyocytes, a monoclonal antibody against smooth muscle myosin heavy chain (Sigma Immunochemicals) for vascular smooth muscle cells, and a monoclonal antibody against vimentin (Sigma Immunochemicals).…”