有机铬对2型糖尿病患者红细胞胰岛素受体的影响

目的 探讨有机铬改善糖代谢的作用机制。方法 将61例血铬正常的健康者作为对照组，63例血铬降低的2型糖尿病（T2DM）患者作为病例组。病例组患者随机分为酵母治疗组（n=32）和安慰剂对照组（n=31），停用原降糖药，仅饮食控制，并每日口服10g啤酒酵母或安慰剂。分别于服药前及服药两周后采用放射性配体结合分析法，以^125I标记的胰岛素（INS）为配体，与红细胞进行受体结合分析。同时测定空腹血铬、空腹血糖及空腹INS水平。结果 与对照组比较，病例组血铬水平显著降低（P〈0．01），^125I-INS与受体的最大特异性结合率降低（P〈0．01），高亲合力受体的结合位点数和低亲合力受体的结合位点数均降低（P〈0．001），空腹INS水平与受体的结合位点数之间呈显著的负相关（r=-0．91，P〈0．05）。与治疗前比较，酵母治疗组的血铬水平增高（P〈0．01），低亲合力受体的结合位点数显著增加（P〈0．01）。结论 有机铬可能通过增加受体的敏感性增加INS与受体的结合率，从而改善胰岛素抵抗，调节糖代谢。

Effect of Organic Chromium on Erythrocytic Insulin Receptor in Patients with Type 2 Diabetes Mellitus

Objective To explore the mechanism that organic chromium improves glycometabolism. Methods A total of 63 patients with type 2 diabetes mellitus and lower serum chromium were selected as the type 2 diabetes group,while 61 healthy subjects with normal serum chromium as the control group. The type 2 diabetes group was subdivided into yeast-treated group (diet control plus daily orally taking 10 grams beer yeast) and placebo group (diet control plus daily orally taking 10 grams placebo). Two weeks later,radioactivities of iodine-labeled insulin and erythrocytic insulin receptor conjugates were tested before and after treatments. Fasting serum chromium,fasting blood glucose,and fasting insulin were measured at the same time. Results Compared with the control group,serum chromium,maximum specific combining rate between iodine-labeled insulin and receptor,and high-and low-affinity receptor combining sites significantly decreased in type 2 diabetes group ( P < 0.01). In the type 2 diabetes group,significantly negative correlation existed between fasting insulin level and receptor-combining sites (r =-0.91,P < 0.05). In the yeast-treated group,serum chromium and low-affinityreceptorcombiningsitessignificantlyincreasedafter treatment (P < 0.01,respectively).Conclusion Organic chromium may increase the combining rates of insulin and receptors by enhancing the sensitivity of receptors, and is therefore able to improve insulin resistance and regulate glycometabolism.