Investigation of Mechanism of Insulin Resistance in Non-obese Type 2 Diabetes / 中国医师杂志

ABSTRACT

Objective To elucidate the role of insulin receptor and its ?-subunit autophosphorylation in evoking insulin resistance in non-obese type 2 diabetes. Methods 14 patients with non-obese type 2 diabetes and 12 healthy subjects were enrolled in this study. Insulin receptor numbers and its insulin affinity in erythrocytes were measured using radio-labelled ligand binding assay described by Comi et al. Insulin receptor autophosphorylation in erythrocytes membrane was initiated by adding insulin and ?- 32 P ATP. Then the membrane proteins were resolved on 7 5% SDS-PAGE and subjected to autoradiography. Results The numbers of high and low affinity receptors in erythrocytes of type 2 diabetes were 21?13 and 955?427 per cell respectively, and they showed no significant difference as compared with control. The high affinity constant(K 1) and low affinity constant(K 2) of insulin receptors in erythrocytes of type 2 diabetes were (1 70?0 93)?10 -9 LM -1 and (1 44?0 86)?10 -7 LM -1 respectively, also displaying no significant difference in comparison with the control. Insulin-induced receptor ? subunit autophosphorylation was 8 02?5 6△A/mg protein in type 2 diabetes, which was lower than that (28 38?15 24)△A/mg protein) in control(P