Effects of stress on immunologic function of Zinc-deficient rats

  Objective   To observe the effects of stress and zinc-deficiency on immunologic function and the related response of rats.

  Methods   Wistar rats were divided into six groups: zinc-deficiency(ZD), stress+zinc-deficency(SZD); pair-fed control(PF), stress+pair-fed control(SPF); control(CT), stress+control(SCT).ZD and SZD were fed zinc-deficient diet(zinc content 2.0 mg/kg), other groups were fed basic diet(zinc content 38.5 mg/kg).After one week, the stress groups received photo-electric stimulation.At the end of experiment, all rats were killed, the weights of immune organs and cortisol levels and T cell proliferation were assayed.

  Results   Cortisol levels were markedly increased under zinc-deiciency and stress conditions, especially in SZD group.The zinc-deficient rats had poor appetite and retarded growth.The weights and the index of thymus and spleen decreased significantly in zinc-deficient groups under stress and non stress conditions.The weights and the index of the immune organs mentioned above were decreased apparently in stress animals compared with those of the corresponding non stress rats.T cell proliferation was markedly decreased in SZD group.

  Conclusion   The immunologic function was decreased under stress and zinc-deficiency conditions; Zinc deficiency worsened the damage of immunologic function by stress.