Effect of dietary level of ascorbic acid on the growth, hepatic lipid peroxidation, and serum lipids in guinea pigs fed polychlorinated biphenyls.

Rats exposed to polychlorinated biphenyls (PCB) or other xenobiotics exhibit an increase in tissue and urinary ascorbic acid, serum cholesterol and hepatic lipid peroxidation. To clarify the physiological role of ascorbic acid in exposure to PCB, we studied the influence of dietary levels of ascorbic acid (30-2,000 ppm) on the growth, serum lipids and hepatic lipid peroxidation in guinea pigs fed 50 ppm PCB-containing diets. The results showed that the growth depression due to PCB was ameliorated by increasing dietary ascorbic acid. The increases in serum cholesterol and phospholipid and in hepatic lipid peroxidation due to PCB were suppressed by larger amounts of ascorbic acid, which inversely correlated with the changes in growth. PCB intake also increased serum levels of cortisol and triglyceride, but these effects were not influenced by dietary level of ascorbic acid. The optimum requirement of ascorbic acid in the guinea pigs fed PCB was 800-2,000 ppm in the diet for the changes in the growth, serum cholesterol and hepatic lipid peroxidation.