AROCLOR 1254 ALTERS THE BINDING OF I-125 LABELED NERVE GROWTH-FACTOR IN PC12 CELLS

The effects of Aroclor 1254, a mixture of polychlorinated biphenyls (PCBs), on nerve growth factor (NGF) receptors and neurite outgrowth in PC12 cells were examined. Aroclor 1254 enhanced the NGF-stimulated neurite elongation and decreased the Kd value for binding of I-125-labeled NGF to the high-affinity NGF receptors. The NGF dose-response curve for neurite outgrowth was also shifted to the left in cells pretreated with Aroclor 1254, suggesting that NGF was more potent in the presence of PCBs. Thus, one mechanism by which PCBs may enhance NGF-stimulated neurotrophic effects is in increasing the affinity of binding of NGF to the high-affinity NGF receptors, which are believed to mediate the neurotrophic effects of NGF. The data suggest that PCBs have the potential to influence the NGF neurotrophic system.