EFFECT OF AROCLOR-1248 AND 2 PURE PCB CONGENERS UPON THE RELEASE OF ARACHIDONIC-ACID FROM THE INTRACELLULAR PHOSPHOLIPIDS OF RAT RENAL TUBULAR CELL-CULTURES

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 [H-3]a rachidonic acid. Studies have been realized with Aroclor 1248 (a comme rcial PCBs mixture with 48% chlorine by weight) and two pure PCB conge ners: 3,3',4,4'-tetrachlorobyphenyl (a coplanar compound) and 2,2',4,4 ',5,5'-hexachlorobiphenyl (a diortho-substituted nonplanar congener). When Aroclor 1248 was added, a relation between Aroclor concentration and arachidonate release to the culture medium was found. This work co ncludes that only the diortho-substituted congener that prefers a nonp lanar configuration can increase the release of [H-3]arachidonic acid from the intracellular stores to the culture medium, while the exposur e of cell cultures to the chosen coplanar congener does not alter the release of [H-3]arachidonic acid to the culture medium in a significan t manner. This means that the toxic effect of PCBs could be due, at le ast in part, to the coplanarity or noncoplanarity of these compounds. (C) 1997 Academic Press.