Effect of antioxidants on the proliferative response of canine lymphocytes in serum from dogs with vitamin E deficiency.

The in vitro effect of vitamin E and 3 other antioxidants--ethoxyquin, 2-mercaptoethanol, and ascorbic acid--on proliferation of canine lymphocytes was examined. Lymphocytes from 2 groups of dogs given a vitamin E-deficient diet or whelped from a bitch fed such a diet were cultured with pooled samples of serum from dogs fed a vitamin E-deficient diet or whelped from a bitch fed such a diet, or normal canine serum, and stimulated with phytohemagglutinin. Added vitamin E enhanced the responsiveness in serum from the dogs with vitamin E deficiency, but not in normal canine serum. A similar effect was noted with added ethoxyquin and 2-mercaptoethanol. Ascorbic acid had no effect on proliferation in either serum pool. These results indicated that depressed lymphocyte responsiveness seen with serum from vitamin E-deficient dogs may, at least in part, be due to a loss of antioxidant activity in this serum.