Abstract
This study was carried out to clarify the effect of dietary vitamin E levels on the depression of vitamin A storage and lipid peroxide formation in rats given PCB.
Weanling male rats of the Sprague Dawley strain were fed the experimental diets containing 0, 0.01 and 0.025% of PCB, and 10 and 25mg% of vitamin E (as α-tocopheryl acetate) for 10 days.
1. Under the conditions used in this study, PCB and vitamin E added to the diets showed no significant effect on body weight gain of rats. The hepatic hypertrophy was observed as PCB content in the diet increased, but it was not depressed by ingestion of diet containing 25mg% vitamin E.
2. PCB administration with vitamin E at a higher level (25mg%) enhanced the concentration of vitamin E in the liver. On the other hand, no significant difference in the vitamin E content of the liver was observed between the animals fed the diets containing 10mg% and 25mg% of vitamin E without PCB.
Vitamin A content in the liver decreased with the increment of PCB in the diet, and it was found that a larger supply of dietary vitamin E did not prevent the depression of vitamin A storge.
3. The TBA value in the liver of rats fed a 0.025% PCB diet increased significantly, and the value was not depressed by the larger supply of dietary vitamin E (2.5 times of usual vitamin E level).
Glutathione peroxidase activities in the whole liver were not varied by PCB administration and the levels of dietary vitamin E. Therefore the activities per gram of the tissue were lowered in the liver enlarged by PCB.
4. The larger supply of dietary vitamin E depressed the content of cytochrome P-450 in the liver microsome which was significantly induced by the ingestion of PCB.
