EFFECT OF VITAMIN-E SUPPLEMENTATION ON THE IMMUNE-RESPONSE DURING CHEMICALLY-INDUCED HEPATOCARCINOGENESIS IN THE RAT

The effect of vitamin E (Vit E), both alpha-tocopherol (alpha-T) and g amma-tocotrienol (gamma-T3), supplementation on splenocyte proliferati on and phagocytic activity of peritoneal macrophages in rats treated w ith diethylnitrosamine (DEN) and 2-acetylaminofluorene (AAF) was inves tigated. Splenocyte proliferation in response to concanavalin A or phy tohemagglutinin and phagocytic activity of peritoneal macrophages in t he DEN/AAF-treated rats were significantly reduced compared with the c ontrol levels. In contrast, mitogenesis and phagocytic activity of per itoneal macrophages were increased significantly in the DEN/AAF-treate d rats supplemented with Vit E; and the vitamin effect was dose depend ent. However, the increases were not so great as those observed in the controls. The highest doses of alpha-T and gamma-T3 used effected the highest phagocytic activity, with alpha-T generally showing a higher activity than gamma-T3. Although long-term Vit E supplementation at ha lf the optimum dose significantly increased mitogenesis, phagocytic ac tivity in the DEN/AAF-treated and control rats was only marginally inc reased.