金属硫蛋白对热应激奶牛血淋巴细胞凋亡基因和HSP70基因表达的影响

he effect of exogenous metallothionein on expression of lymphocytes apoptosis gene and HSP70 in dairy cattle was conducted with 25 lactating Chinese Holstein cows, which were randomly divided into five groups (A, B, C, D and E), and supplemented with 0, 16.0, 24.0, 32.0 and 40.0 mg Zn-MT respectively by intravenous injection. Blood samples were collected at 1st, 7th and 14th day, and the levels of HSP70, Bcl-2, Bax and p53 gene expression in lymphocytes were determined. The milk yield of the cows in group B was greater than those in group A, C, D and E by 20.94%(P＜0.05), 15.83%(P＞0.05), 10.94%(P＞0.05) and 8.85%(P＞0.05) respectively. The level of HSP70 gene expression in group D was greater(P＜0.05) than those in group A, and there were no significant diffences(P＞0.05) in HSP70 gene expression among group A and B, C, E. The level of Bcl-2 gene expression in group B, C, D and E were greater than those in group A, and significant diffences(P＜0.05) was determined between group A and C. The level of Bax gene expression in group B and D were lower than those in group A by 22.00%(P＞0.05) and 13.00%(P＞0.05), while the level of p53 gene expression in group C and E were lower than those in group A by 22.00%(P＞0.05) and 34.00%(P＞0.05) respectively. It is suggested that exogenous Zn-MT can improve milk producing ability and regulate the levels of HSP70, Bcl-2, Bax and p53 gene expression of dairy cattle, and showing a dose-dependent manner.