EFFECT OF ZINC DEFICIENCY ON THE APOPTOSIS OF IMMUNOCYTES IN THREE WEEKS OLD RATS / 营养学报

ABSTRACT

Objective: To observe the effects of dietary zinc deficiency on the apoptosis of immunocytes in 3 weeks old rats and study the underlying mechanism. Methods: A zinc-deficient growing rat model was developed. Using TUNEL(terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling) method, the apoptosis of thymocytes and spleen lymphocytes was checked. The expression of bcl-2, bax mRNA in thymus and spleen was detected by RT-PCR. Results: Compared with zinc adequate(ZA) and paired-fed(PF) groups, the percentage of apoptosis cells in thymus and spleen of zinc-deficient(ZD) rats was obviously higher, and the thymus and spleen of ZD rats had a higher expression of bax mRNA. Zinc supplementation could reverse these changes. Conclusion: Dietary zinc deficiency leads to the increase of apoptosis of lymphocytes in thymus and spleen. One important mechanism is that the thymus and spleen have higher expression of bax mRNA, which causes the decrease of bcl-2/bax ratio.