锌对胰岛素抵抗靶细胞活力和葡萄糖消耗量影响

目的 探讨锌对胰岛素抵抗靶细胞活力和葡萄糖消耗量的影响.方法 建成HepG2细胞、3T3-L1细胞和L6成肌细胞胰岛素抵抗模型后,用10^-7mol/L胰岛素和不同浓度锌(0、20、50、100、200、400 μmol/L)孵育细胞,通过MTT法和葡萄糖氧化酶法测定基础状态和胰岛素刺激状态下3种胰岛素抵抗细胞葡萄糖的消耗量.结果 不同剂量的锌孵育3种细胞3 h后,200、400 μmol/L的锌可明显抑制各组细胞的活力(P< 0.05);50~100 μmol/L的锌干预3 h能在不同程度上提高HepG2、3T3-L1正常细胞和胰岛素抵抗细胞的葡萄糖消耗量,但其作用效果明显低于胰岛素;其中100 μmol/L的锌与胰岛素共同作用的效果分别优于胰岛素或锌单独作用的效果(P< 0.05);对于L6肌细胞,20、50和100 μmol/L锌均能明显提高基础状态下正常细胞和胰岛素抵抗细胞的葡萄糖消耗量(P< 0.05);仅有20 μmol/L锌和胰岛素共同作用的效果优于胰岛素或锌单独作用的效果(P< 0.05).结论 不同浓度的锌可以在一定程度上提高3种胰岛素抵抗的靶细胞葡萄糖摄取量,且不同的细胞具有不同的适宜作用剂量.

Effects of zinc on cell viability and glucose consumption of insulin-resistant cells

Objective To elucidate the effects of zinc on cell viability and glucose consumption of insulin-resistant cells.Methods After the establishment of insulin-resistant cell model,the HepG2,3T3-L1,and L6 cells of the models were exposed to different doses of zinc(0,20,50,100,200,and 400 μmol/L) for 3 hours; then cell viability was determined with 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H- tetrazolium bromide(MTT) assay and glucose consumption was detected with glucose oxidase method.Results After 3 hours' incubation with high concentration of zinc(200 and 400 μmol/L),cell viability was down-regulated significantly(P< 0.05).Zinc at the concentrations of 50-100 μmol/L could increase glucose consumption of HepG2 and 3T3-L1 cells in both normal and insulin-resistant state; however,the effect was weaker than that of insulin.Compared with insulin or 100 μmol/L zinc treatment alone,the combined treatment of the two agents showed stronger effect(P< 0.05).For L6 myotubes,zinc at the concentrations of 20-100 μmol/L showed stimulatory effect in both normal and insulin-resistant cells(P< 0.05) and an enhanced effect was observed when zinc at 20 μmol/L combined with insulin in comparison with insulin or zinc treatment alone(P< 0.05).Conclusion Zinc at certain doses plays a promotive role in glucose consumption of HepG2,3T3-L1,and L6 insulin-resistant cells,but its effective dose is different among the three cell lines.