Changes in macrophage and lymphocyte functions in guinea-pigs after different amounts of vitamin E ingestion

Vitamin E is the main biological lipid-soluble antioxidant and plays a cruc ial role in the maintenance of the immune system. In the present work, twen ty-one guinea-pigs (3-weeks-old) were distributed into three groups, which during 5 weeks ingested different amounts of vitamin E (/kg diet): 15 mg (l ow vitamin E diet), 150 mg (medium vitamin E diet; control) or 1500 mg (hig h vitamin E diet). The function of lymphocytes and macrophages were then st udied. In macrophages obtained from the peritoneum several steps of the pha gocytic process (chemotaxis, ingestion and superoxide anion production) wer e assayed, as well as chemotaxis and proliferation of peritoneal and spleen lymphocytes. The results indicate that with respect to the medium vitamin E diet, low ingestion of vitamin E causes a decrease in chemotaxis and prod uction of superoxide anion by macrophages and an increase in the phagocytic capacity. With the high vitamin E diet an increase in macrophage and lymph ocyte chemotaxis, superoxide anion production and lymphoproliferative capac ity, as well as a decrease in phagocytosis, were observed. Therefore, diet supplementation with higher than usual levels of vitamin E appears to be be neficial for the immune system.