EFFECT OF STRUCTURALLY DIVERSE PEROXISOME PROLIFERATORS ON RAT HEPATIC SULFOTRANSFERASE

Exposure to perfluorocarboxylic acids, pthalate esters, and some hypol ipidemic agents results in the proliferation of peroxisomes in the rod ent liver. The structural diversity of these compounds suggests mechan istic diversity in their toxicity as well. To establish reliable bioma rkers of peroxisome proliferation (PP) in compounds with distinct chem ical toxicities, this study investigated the effect of in vivo exposur e to perfluoro-n-octanoic acid, perfluoro-n-decanoic acid, di(2-ethylh exyl)phthalate (DEHP) and clofibrate on two-dimensional electrophoreti c protein patterns of rat hepatic sulfotransferases, ST1A1, ST1C1 and ST2A1. After exposure to peroxisome proliferative doses, both ST1A1 an d ST1C1 abundance in whole liver homogenates was significantly reduced , but only as a result of perfluorocarboxylic acid exposure. The well- established PPs, DEHP and clofibrate had no effect on sulfotransferase expression whatsoever, The observed down-regulation of these STs is s ignificant with respect to their normal detoxication activities and it s potential correlation to carcinogenesis warrants further study, The present investigation supports previous studies that demonstrate the u nique features of perfluorocarboxylic acid toxicity, relative to class ic peroxisome proliferators and endorses the continued use of 2D prote in-mapping of STs and other proteins as biomarkers of chemical toxicit y.