Glutathione, glutathione S-transferases activity and immune responses in chickens following exposure to vitamin A during development and fed excess vitamin E

The objectives of the experiments were to explore the possibility of utilizing the nutrients, vitamins A and E, during embryogenesis or post-hatching to influence glutathione S-transferase (GST) activity and glutathione (GSH) concentration, and consequently influence growth and immune responses in chickens.; The developments of hepatic GST activity and GSH concentration during embryogenesis and post-hatching were examined. Hepatic GST activity gradually decreased during embryogenesis. However, hepatic GST activity significantly increased in the first six days of the post-hatching period. The pattern of hepatic GSH concentration during embryogenesis and post-hatching period was very similar to the developmental changes in hepatic GST activity.; The relationship between hepatic GST activity and GSH concentration was determined by the method of fasting. Fasting decreased both hepatic GST activity and GSH concentration. It also confirmed the finding of the previous study that a strong relationship existed between hepatic GST activity and GSH concentration.; When hatching eggs were dipped in retinol acetate solution on day 2 or 4 of the incubation period, hatchability was not affected. Production of IgM and IgG and delayed hypersensitivity response (DHR), an indicator of cell-mediated immunity in bird, were not affected. However, exposure of the developing embryo to retinoic acid solutions (10, 100 1000 ng/egg) on day 4 or 11 of the incubation period, severely depressed hatchability. These levels of retinoic acid did not affect the growth of birds post-hatching. Humoral immunity was increased while cell-mediated immunity was depressed by the toxic doses of retinoic acid.; The effect of vitamin E on body weight, GST activity, GSH concentration and the immune response in birds was evaluated. Feeding birds with 300 mg vitamin E/kg did not change body weight, GST activity and GSH concentration in different organs, humoral immunity and DHR.; The combination of vitamins A and E on hatchability and the above parameters was studied. Hatchability and body weight were not affected by dipping hatching eggs in retinoic acid solution (10 ng/egg). However, subsequent decreased humoral immunity and enhanced cell-mediated immunity in birds demonstrated that retinoic acid did affect the development of embryo during embryogenesis. Excess vitamin E increased humoral immunity but cell-mediated immunity was not affected.