Effect Of Zinc And Vitamin A On The Immune Function Of Mice

Objective: To observe the co-association effect of zinc and vitamin A on the mice immune function, the mice model was established, in order to provide the theory guiding the scientific and reasonable co-intervention of zinc and vitamin A.Methods: The BALB/c mice were randomly divided into five groups: zinc and vitamin A deficiency-group(ZAD),zinc-deficiency group(ZD), vitamin A-deficiency group(AD), vitamin A-deficiency but zinc-excess group(ZE) and control group. At the end of 7th week, the blood of mice was gotten for measuring the levels of zinc and vitamin A in serum; Spleen cells was separated for in vitro culture to measure the plaque forming cells,the proliferative response to PHA and the activity of NK cells;The subgroup of spleen lymphocytes was measured by Immunohistochernistry and the apoptosis of thymus lymphocytes was measured by comet assay.Results: The weight of spleen and thymus in ZAD, ZD and ZE decreased remarkably compared with that in control group. The thymus coefficient in ZE decreased remarkably compared with that in control group, but there was no significant difference in the spleen coefficient among ZAD, ZD, AD, ZE and control group. In ZAD, the levels of vitamin A and zinc in serum, plaque forming cells, the proliferative to PHA of T lymphocytes and the activity of NK cells decreased remarkably compared with those in AD, ZD and control group. In ZE,the level of vitamin A, plaque forming cells,the proliferative to PHA of T lymphocytes and the activity of NK cells decreased remarkably compared with those in control group,nevertheless, the level of serum zinc in ZE was higher than that in control group; the amount of CD3+T cells and CD4+T cells in ZAD, ZD, ZE decreased remarkably compared with that in control group, and the amount of CD4+T cells in AD decreased remarkably also, but there was no significant difference in the amount of CD3+T cells and CD4+T cells among ZAD, ZD and AD. There was no significant difference in the amount of CD8+T cells among ZAD, ZD, AD, ZE and control group. The apoptosis rate of thymus lymphocytes in ZAD, ZD, AD and ZE was higher than that in control group, and the apoptosis rate of thymus lymphocytes in ZAD was higher than that in ZD and AD. The DNA damage rate in ZAD, ZD and ZE was higher than that in control group. There was no significant difference in the DNA damage rate among ZAD, AD, and ZD.Conclusion: Marginal zinc and vitamin A deficiency can do damage to both antibody-mediated immunity and cell -mediated immunity, and the extent of the damage to immune function was greater than zinc or vitamin A deficiency. Marginal vitamin A deficiency with zinc excess can also do damage to both antibody-mediated immunity and cell -mediated immunity. The effect of zinc and vitamin A on the apoptosis of thymus lymphocytes may be one of the mechanisms by which they affect immune function.