三氯化铬对2型糖尿病患者红细胞胰岛素受体的影响

目的探讨三价铬改善糖代谢的作用机制。方法以血铬正常的健康人作对照，将63例血铬降低的T2DM患者的红细胞悬液与不同浓度的三氯化铬进行体外孵育，测定孵育前、后碘标INS与红细胞INS受体结合物的放射性，并进行Scatchard分析。结果T2DM组较对照组血铬显著降低（P〈0．01）；碘标INS与受体的最大特异性结合率及r1、r2均降低（P〈0．01），且空腹INS水平与受体的结合位点之间呈显著的负相关（r=-0．91，P〈0．05）。加入三氯化铬后，与“0”浓度组比较，“100”浓度组仅r1增加（P〈0．01），而“200”及“400”浓度组的最大特异性结合率及r1、r2均增加，k1及k2降低，均有统计学差异。结论三价铬可能通过增加受体的敏摩洼而增加INS与受体的结合率，从而改善IR调节糖代谢。

Influence of chromium trichloride on erythrocytic insulin receptor of patients with type 2 diabetes mellitus

Objective] To explore the action mechanism of trivalent chromium improving glycometabolism. Methods] With normal serum chromium objects as controls, erythrocytic suspensions from 63 cases with type 2 diabetes and lower serum chromium were incubated in vitro with different concentrations of chromium trichloride. Radioactivity of iodine labeled insulin and erythrocytic insulin receptor conjugate before and after s/he incubation was measured and Scatchard analysis was done. Results] Compared with controls, serum chromium, maximum specific combining rate between iodine labeled insulin and receptor, and high and low affinity receptor combining sites (r1 and r2) were reduced in type 2 diabetes group (P <0.01). In type 2 diabetes group the correlation between fasting insulin level and receptor combining sites presented obviously negative correlation (r =-0.91, P <0.05). After adding chromium trichloride, compared with 0 concentration group only r1 was increased in 100 concentration group (P <0.01). In 200 and 400 conce ntration groups maximum specific combining rates, r1 and r2 were increased, but two receptor affinity constants (k1 and k2) were reduced (P <0.05). Conclusion] Trivalent chromium may increase the combining rate between insulin and receptor through enhancing receptor's sensitivity so as to improve insulin resistance and to regulate glycometabolism.