Changes in CD4(+)CD8(-)/CD4(-)CD8(+) ratio and humoral immune functions invitamin B-12-deficient rats

To clarify the role of vitamin B-12 in the function of cell-mediated and hu moral immune functions, the splenocytes expression of CD4, CD8 and serum C3 , IgM, IgG concentrations were examined in vitamin B-12-deficient rats, and the effect of the administration of methylcobalamin was also studied. The CD4(+)CD8(-)/CD4(-)CD8(+) ratio in splenocytes was significantly higher in vitamin B12-deficient rats than in control rats (p < 0.05). The value in th e 48 hours after methylcobalamin administration group, was within the norma l range (p < 0.05). From these results, the elevation of the CD4(+)CD8(-)/C D4(-)CD8(+) ratio by vitamin B-12-deficiency was confirmed in rats. The ser um C3, IgM and IgG concentrations were lower in the vitamin B-12-deficient group than in the control group. These findings suggest that vitamin B-12 p lays a role in maintaining the immune function in rats.