ELEVATED CONCENTRATIONS OF ALPHA-TOCOPHEROL, ASCORBIC-ACID, AND SERUM-LIPIDS IN RATS FED POLYCHLORINATED-BIPHENYLS, CHLOROBUTANOL, OR PHENOBARBITAL

Experiments were conducted with growing rats to investigate the effects of dietary 0.05% polychlorinated biphenyls (PCB), 0.3% chlorobutanol (Chloretone), and 0.2% phenobarbital sodium on intestinal absorption of alpha-tocopherol and serum and tissue lipids, and the influence of dietary 5% pectin and 0.2% ethyl p-chlorophenoxyisobutyrate (clofibrate) on the changes in these lipids due to dietary 0.4% Chloretone. Dietary addition of PCB increased serum concentrations of alpha-tocopherol, cholesterol, and phospholipids. These were mainly attributed to the increments in the fraction of high-density lipoproteins. PCB intake increased tissue alpha-tocopherol and apparent absorption of alpha-tocopherol from intestine. Similar changes in serum and tissue lipids and in intestinal absorption of alpha-tocopherol were observed with dietary Chloretone and phenobarbital. Dietary clofibrate and pectin depressed the increase in serum concentrations of these lipids by Chloretone. Changes in serum levels of alpha-tocopherol, cholesterol, and phospholipids correlated with those in apparent absorption of alpha-tocopherol. These results suggest that the increase in serum cholesterol and phospholipids due to xenobiotics relates to the increase in serum and tissue alpha-tocopherol.