Testa I, Rabini R A, Fumelli P, Bertoli E, Mazzanti L
Department of Internal Medicine, University of Ancona School of Medicine, Italy.
J Clin Endocrinol Metab. 1988 Dec;67(6):1129-33. doi: 10.1210/jcem-67-6-1129.
An alteration in the enzymatic properties of the erythrocyte membrane acetylcholinesterase (AchE) and Na+,K+-ATPase has been described in experimental diabetes mellitus. We studied erythrocyte membrane fluidity and AchE and Na+,K+-ATPase activities in 15 insulin-dependent diabetic patients and 11 normal subjects. Fluidity was assessed by fluorescence polarization, using 1,6-diphenyl-1,3,5-hexatriene as a probe, and AchE and Na+,K+-ATPase activities were measured enzymatically. We found a significant increase in the enzymatic activity of AchE and a change in its enzymatic properties in diabetic patients compared with those in normal subjects. AchE activity correlated inversely with membrane fluorescence polarization, which was decreased in the diabetic patients, indicating an increase in membrane fluidity. Na+,K+-ATPase activity was reduced in the diabetic patients and correlated positively with the fluorescence polarization values. We hypothesize that the abnormal dynamic properties of the erythrocyte membrane may play a major role in determining the described change in enzymatic activity.
实验性糖尿病中已发现红细胞膜乙酰胆碱酯酶（AchE）和Na⁺,K⁺-ATP酶的酶学特性发生改变。我们研究了15例胰岛素依赖型糖尿病患者和11名正常受试者的红细胞膜流动性以及AchE和Na⁺,K⁺-ATP酶活性。使用1,6-二苯基-1,3,5-己三烯作为探针，通过荧光偏振评估流动性，并通过酶法测量AchE和Na⁺,K⁺-ATP酶活性。我们发现与正常受试者相比，糖尿病患者的AchE酶活性显著增加且其酶学特性发生改变。AchE活性与膜荧光偏振呈负相关，糖尿病患者的膜荧光偏振降低，表明膜流动性增加。糖尿病患者的Na⁺,K⁺-ATP酶活性降低，且与荧光偏振值呈正相关。我们推测红细胞膜的异常动态特性可能在决定所述酶活性变化中起主要作用。
