Selective fatty acid release from intracellular phospholipids caused by PCBs in rat renal tubular cell cultures

Abstract

The purpose of this study was to explore the influence of different polychlorinated biphenyls (PCBs) upon the release of oleic and palmitic acid from the intracellular lipids, which were previously labeled with [ 3H]oleic or [ 3H]palmitic acid, respectively. Studies have been realized with Aroclor 1248 (a commercial PCB mixture with 48% chlorine by weight), and two pure PCB congeners: 3,3′,4,4′-tetrachlorobiphenyl (a non-ortho-substituted planar congener) and 2,2′,4,4′,5,5′-hexachlorobiphenyl (a di-ortho-substituted nonplanar congener). The treatment of cells with Aroclor 1248 increased [ 3H]oleic acid release in a concentration-dependent manner. Our results showed that only the di-ortho-substituted congener which prefers a nonplanar configuration stimulated the release of [ 3H]oleic acid from the intracellular phospholipids to the culture medium, while the exposure of cell cultures to the chosen non-ortho-substituted coplanar congener did not alter the release of [ 3H]oleic acid to the culture medium. Finally, none of the PCBs studied could increase the release of [ 3H]palmitic acid from the intracellular stores significantly. The possibility that these differential alterations in the fatty acid release affect cell function during PCB exposure should therefore be postulated.