Evidence for amelioration of steroid-mediated immunosuppression by ascorbic acid.

Four experiments were conducted to determine if supplemental ascorbic acid (AA) would ameliorate the immunosuppression induced by exogenous cortisol (COL). Supplemental AA was provided in the diets at levels of 0 and 1000 ppm. Administration of COL significantly lowered plasma AA at both 0 and 10 days postimmunization, and AA supplementation elevated plasma AA at both times. Cortisol-treated chicks exhibited significantly reduced agglutinins to sheep red blood cells but not to Brucella abortus. Supplemental AA significantly ameliorated the immunosuppression associated with exogenous COL and may serve as an antiimmunosuppressive agent in the chicken.