NON-SPECIFIC IMMUNOMODULATORY EFFECTS OF DIETARY VITAMIN C ON GROUPER EPINEPHELUS AWOARA

The non specific humoral and cellular immunomodulatory effects of dietary vitamin C(Vc) on grouper Epinephelus awoara were studied.Grouper were provided with frozen diet fish(trash fish)supplemented with different doses of vitamin C(0,500,1?000,1?500,2?000?mg·kg -1 )continuously for 20 weeks.It was found that the total blood leucocyte number and the composition proportion of different leucocytes including lymphocyte,neutrophil and monocyte were unaffected by vitamin C.The activity of classical haemolysis of serum complement to sheep red blood cells(SRBC)significantly increased with the increase of vitamin C( p 0.01).However,no difference was seen in the bactericidal complement activity of serum among fish treated with dietary vitamin C.The non specific cellular defence mechanisms were examined.Blood leucocyte phagocytosis to Staphylococci aureus and phagocytic activity of adherent head kidney cells were unaffected by dietary vitamin C.