Effect of Aroclor 1248 and Two Pure PCB Congeners upon the Release of Arachidonic Acid from the Intracellular Phospholipids of Rat Renal Tubular Cell Cultures

Abstract

The exposure of rat tubular cell cultures to different polychlorinated biphenyls (PCBs) stimulated the release of arachidonic acid from the intracellular phospholipids, which were previously labeled with [3H]ara chidonic acid. Studies have been realized with Aroclor 1248 (a commercial PCBs mixture with 48% chlorine by weight) and two pure PCB congeners: 3,3′,4,4′-tetrachlorobyphenyl (a coplanar compound) and 2,2′,4,4′,5,5′-hexachlorobiphenyl (adiortho-substituted nonplanar congener). When Aroclor 1248 was added, a relation between Aroclor concentration and arachidonate release to the culture medium was found. This work concludes that only thediortho-substituted congener that prefers a nonplanar configuration can increase the release of [3H]arachidonic acid from the intracellular stores to the culture medium, while the exposure of cell cultures to the chosen coplanar congener does not alter the release of [3H]arachidonic acid to the culture medium in a significant manner. This means that the toxic effect of PCBs could be due, at least in part, to the coplanarity or noncoplanarity of these compounds.