Shono N I, Rabinovich S E, Platonova L V, Diuzheva T G
Vopr Med Khim. 1994 Sep-Oct;40(5):45-8.
Erythrocytes of patients with insulin-dependent diabetes mellitus contained two forms of aldose reductase a and b (EC No. 1.1.1.21) (the key enzyme in the sorbitol pathway of glucose utilization) as compared with those of healthy donors in whom the form b of the enzyme was only found. The aldose reductase a exhibited a higher maximal rate (Vmax = 16.7 +/- 3.2 IU/D280) and a lower substrate affinity (Km = 6.5 = 19 mM) than the enzyme b, Vmax = 43.8 +/- 0.6 IU/D280, Km = 3.0 = 4.0 mM, respectively. More severe development of the disease was observed in the patients whose erythrocytes contained only aldose reductase a (HbA1c = 14.56 +/- 0.69%) as compared with those in whom the enzyme a and b were found (HbA1c = 11.5 +/- 0.4%). Kinetic parameters of the enzyme showed that aldose reductase a may be active in hyperglycemia of diabetes mellitus, thus contributing to intensification of the sorbitol pathway in these patients.
与仅发现醛糖还原酶b型的健康供体相比，胰岛素依赖型糖尿病患者的红细胞含有两种形式的醛糖还原酶a和b（酶编号1.1.1.21）（葡萄糖利用的山梨醇途径中的关键酶）。醛糖还原酶a的最大反应速率（Vmax = 16.7 +/- 3.2 IU/D280）高于酶b，底物亲和力（Km = 6.5 = 19 mM）低于酶b，酶b的Vmax = 43.8 +/- 0.6 IU/D280，Km = 3.0 = 4.0 mM。与同时发现酶a和b的患者（糖化血红蛋白A1c = 11.5 +/- 0.4%）相比，红细胞中仅含有醛糖还原酶a的患者（糖化血红蛋白A1c = 14.56 +/- 0.69%）疾病进展更为严重。该酶的动力学参数表明，醛糖还原酶a可能在糖尿病的高血糖状态下具有活性，从而促使这些患者的山梨醇途径增强。
