Dietary taurine potentiates polychlorinated biphenyl-induced hypercholesterolemia in rats

The effect of dietary taurine on cholesterol metabolism and the distributio n of lipoprotein-cholesterol in serum of rats fed a diet containing polychl orinated biphenyls (PCB) was examined. Young male Wistar rats (60 g) were f ed diets containing 0.2 g/kg diet of PCB and/or 30 g/kg diet of taurine for 15 days. The experiment was performed as the 2 (PCB) X 2 (taurine) factori al design. The addition of PCB elevated serum levels of total- and HDL-chol esterol and apolipoprotein A-I, which is a major apolipoprotein of HDL. Sim ultaneous supplementation of taurine with PCB amplified the increase of the serum level of total- and HDL-cholesterol. Hepatic concentrations of chole sterol and total lipids were significantly elevated by the supplementation of PCB, and taurine significantly amplified these increases caused by PCB. PCB suppressed hepatic cholesterol 7 alpha -hydroxylase (CYP7A1) gene expre ssion, and taurine induced CYP7A1 gene expression. Taurine also enhanced PC B-induced elevation of malic enzyme mRNA in the liver. These results sugges t that taurine enhanced PCB-induced hyper-a-cholesterolemia and that taurin e has a role in increasing HDL-cholesterol. (C) 2001 Elsevier Science Inc. All rights reserved.