VITAMIN CONCENTRATION AND FUNCTION OF LEUKOCYTES FROM DAIRY CALVES SUPPLEMENTED WITH VITAMIN-A, VITAMIN-E, AND BETA-CAROTENE IN-VITRO

Blood neutrophils and pulmonary alveolar macrophages, isolated from ca lves at 3 and 6 wk of age, were cultured in medium without added vitam ins or supplemented with 100 mug/dl of vitamin A, 1000 mug/dl of vitam in E, 100 mug/dl of vitamin A plus 1000 mug/dl of vitamin E, or .25 mu g/dl of beta-carotene plus 1000 mug/ dl of vitamin E. Macrophage bacte ricidal activity improved with supplementation of vitamins A plus E co mpared with supplementation of beta-carotene plus E or vitamin E at wk 3. Neutrophil bactericidal activity decreased with all vitamin E trea tments at wk 3 and with vitamins E or A plus E at wk. 6. Neutrophil ph agocytosis improved at wk 3 with supplementations of vitamins A, E, an d A plus E. The chemotactic index improved with beta-carotene and vita min E compared with vitamin E alone at wk 3 and at wk 6 with vitamin E compared with vitamin A and control treatments. Retinol content of ne utrophils varied at wk 3, but, by wk 6, cells supplemented with vitami ns A, E, or A plus E had greater retinol concentrations than control c ells. Neutrophil alpha-tocopherol concentrations at wk 3 increased fro m those of controls with supplementation of vitamin E or beta-carotene and vitamin E, but, at wk 6, vitamin E-supplemented cells were differ ent only from vitamin A-supplemented cells. These data suggest that op timal plasma concentrations of vitamins A and E exist for leukocyte fu nction.