醛糖还原酶抑制剂治疗糖尿病周围神经病变的临床观察

目的:观察醛糖还原酶抑制剂依帕司他治疗糖尿病周围神经病变(DPN)的疗效。方法:DPN患者90例,随机分为治疗组46例(口服依帕司他片),对照组44例(肌肉注射维生素B12),记录治疗前后患者的主观症状、体征及肌电图检查神经传导速度的改善情况。结果:经8周治疗后,证明依帕司他对糖尿病周围神经病变自觉症状、体征及周围神经传导速度的改善有较好疗效,其疗效优于对照组,两组疗效差异有显著性。结论:醛糖还原酶抑制剂依帕司他治疗糖尿病周围神经病变是一种安全、有效的药物。     

荧光法动态观察糖尿病大鼠红细胞醛糖还原酶活性

目的比较测定醛糖还原酶(AR)活性的两种荧光法(碱终止法和酸终止法)的差异,应用其中较好的一种动态观察糖尿病(DM)大鼠红细胞AR活性。方法SD大鼠随机等分为四组正常对照组和DM20、40、60d组,用辅酶(NADPH或NADP)、DL甘油醛、磷酸缓冲液等组成各自的反应体系,比较碱终止法和酸终止法测定AR活性的灵敏度和重复性,择其优者测定各组大鼠红细胞AR活性。结果NADP和NADPH浓度相同时酸终止法所测荧光值较高;辅酶浓度在0～400μmol/L时标准曲线呈线性;酸终止法标准曲线的批内和批间变异系数分别为0.83%和2.28%,碱终止法为17.88%和16.69%,两法所测标本的批内和批间变异系数分别为4.25%、7.12%和1.13%、13.07%;高氯酸可消除血红蛋白对荧光的影响;DM组AR活性较正常对照增高(P<0.05),且随病程延长活性增加,但DM组间AR活性无统计学差异;血糖与AR活性正相关(r=0.873)。结论酸终止法较碱终止法简便、灵敏、准确、稳定。DM大鼠红细胞AR活性增高,并随病程延长有增加的趋势;提示AR活性的动态观察有可能作为糖尿病并发症发展进程的监测指标。     

Glucose-induced hyperproliferation of cultured rat aortic smooth muscle cells through polyol pathway hyperactivity

Aims/hypothesis. The protein kinase C (PKC), platelet-derived growth factor (PDGF) and polyol pathway play important parts in the hyperproliferation of smooth muscle cells, a characteristic feature of diabetic macroangiopathy. The precise mechanism, however, remains unclear. This study investigated the relation between polyol pathway, protein kinase C and platelet-derived growth factor in the development of diabetic macroangiopathy. Methods. Smooth muscle cells were cultured with 5.5 or 20 mmol/l glucose with or without an aldose reductase inhibitor, epalrestat, or a PKC-β specific inhibitor, LY333 531. Protein kinase C activities, the expression of PKC-βII isoform and PDGF-β receptor protein, free cytosolic NAD⁺:NADH ratio, the contents of reduced glutathione, and proliferation activities were measured. Results. Smooth muscle cells cultured with 20 mmol/l glucose showed statistically significant increases in protein kinase C activities, the expression of PKC-βII isoform and PDGF-β receptor protein, and proliferation activities, compared with smooth muscle cells cultured with 5.5 mmol/l glucose. Although epalrestat and LY333 531 inhibited protein kinase C activation induced by glucose to the same degree, the effects of epalrestat on proliferation activities and expression of the PDGF-β receptor were more prominent than those of LY333 531. Epalrestat improved the glucose-induced decrease in free cytosolic NAD⁺:NADH ratio and reduced glutathione content, but LY333 531 did not. The increased expression of membranous PKC-βII isoform was normalized by epalrestat. Conclusion/interpretation. These observations suggest that polyol pathway hyperactivity contributes to the development of diabetic macroangiopathy through protein kinase C, PDGF-β receptor, and oxidative stress, and that an aldose reductase inhibitor has a therapeutic value for this complication. [Diabetologia (2001) 44: 480–487] Received: 2 October 2000 and in revised form: 13 December 2000     

An aldose redutase inhibitor prevents the intimal thickening in coronary arteries of galactose-fed beagle dogs

Aims/hypothesis. Although increased polyol pathway activity has been implicated in the pathogenesis of diabetic microangiopathy, the relation with diabetic macroangiopathy remains unclear. Galactose feeding is known to stimulate the polyol pathway and to develop abnormalites similar to those in diabetic microangiopathy. Our study was conducted to investigate whether an activation of polyol pathway by long-term treatment with galactose produced morphological changes in coronary arteries of dogs and the effect of an aldose reductase inhibitor, epalrestat, was also studied.¶Methods. Dogs received either normal chow or chow containing 30 % galactose with or without epalrestat given orally (20 or 50 mg · kg^–1). After 44 months, morphometric analyses of coronary arteries were carried out and the galactitol contents in aortas were measured.¶Results. The ratio of areas of the intimal layer to those of the medial layer, an indicator of intimal thickening, was statistically significantly increased in galactose-fed dogs compared with control dogs. Galactose-fed dogs had a remarkable accumulation of galactitol in their aortas. These morphological and biochemical deficits were reduced by treatment with epalrestat.¶Conclusion/interpretation. This report morphologically shows diabetes-like macrovascular abnormalities in galactosaemic animals, suggesting that polyol pathway hyperactivity is closely related to the development of diabetic macroangiopathy, which could be prevented by aldose reductase inhibition. [Diabetologia (1999) 42: 1404–1409]     

不同镇痛方式对开胸手术患者红细胞醛糖还原酶和血浆葡萄糖及脂质过氧化物的影响

目的:比较硬膜外和静脉镇痛对开胸手术患者红细胞醛糖还原酶(AR)活性和血浆葡萄糖(Glu)及脂质过氧化物(MDA)浓度的影响. 方法:42例在静脉全麻复合硬膜外阻滞麻醉下行开胸食道癌手术患者随机分为Ⅰ、Ⅱ两组,每组21例.术后,Ⅰ组行静脉镇痛(芬太尼15μg /kg),Ⅱ组行硬膜外镇痛(0.125%罗哌卡因混合2μg/ml芬太尼).在麻醉前(T0)、手术开始60min(T1)、术后60min(T2)、术后1d(T3)和术后2d(T4)抽取静脉血,测定AR活性及Glu和MDA水平,采用视觉模拟评分(VAS)测定术后4、12、24、48h镇痛效果. 结果:①两组患者术后镇痛效果均良好,但Ⅰ组患者术后12、24h VAS评分明显高于Ⅱ组(P<0.05),总按压次数明显高于Ⅱ组(P<0.01).②与T0值相比,T3时Ⅰ组患者红细胞AR活性显著升高(P<0.01),Ⅱ组患者此酶活性无明显上升(P>0.05);此时Ⅰ组患者AR活性明显高于Ⅱ组(P<0.05).③与T0值相比,两组患者血糖值均从T1 时开始升高(P<0.05),至T3时达峰值(P<0.01),T4时点Ⅱ组患者的血糖值下降至术前水平(P>0.05),而Ⅰ组仍未恢复(P<0.05);T3 、T4 时Ⅰ组血糖值明显高于Ⅱ组(P<0.05).④Ⅰ组患者血浆MDA值在T3时点明显升高(P<0.01),Ⅱ组患者的MDA值无明显变化(P>0.05),组间比较,有统计学意义(P<0.05). 结论:与静脉镇痛相比较,开胸手术后采用硬膜外镇痛,能降低术后血糖与MDA水平和AR活性,从而减轻红细胞的氧化损伤.     

阿托伐他汀对高葡萄糖诱导的血管平滑肌细胞增殖的抑制作用

目的研究阿托伐他汀对醛糖还原酶(AR)和核因子NF-κB的表达及血管平滑肌细胞增殖的影响,探讨阿托伐他汀抗细胞增殖的可能机制。方法用高浓度葡萄糖诱导大鼠血管平滑肌细胞(VSMC)AR基因表达,然后加入不同浓度的阿托伐他汀,培养3d后用台盼蓝染色行细胞计数。并采用RT-PCR、免疫组化、原位杂交等方法,观察阿托伐他汀对NF-κB和AR基因表达及VSMC增殖的影响。结果1)随着阿托伐他汀浓度的提高,VSMC计数逐渐减少。2)正常浓度葡萄糖(5·6mmol/L)时,NF-κB表达不明显,高浓度葡萄糖(22·5mmol/L)时,NF-κB表达强阳性,阿托伐他汀则可明显抑制这一表达,0·1μmol/L阿托伐他汀时,NF-κB表达即有降低,10μmol/L阿托伐他汀几乎完全抑制NF-κB的表达。3)高浓度葡萄糖可明显诱导AR基因的表达,阿托伐他汀对其表达有抑制作用,且呈剂量依赖性。与高浓度葡萄糖组相比,阿托伐他汀0·1、1、10μmol/L分别使VSMC的ARmRNA下调12%、45%和80%(P均<0·05)。结论1)阿托伐他汀可抑制VSMC增殖。2)阿托伐他汀可抑制AR及NF-κB的表达。3)阿托伐他汀可能是通过抑制AR及NF-κB的表达继而抑制VSMC的增殖。     

灯盏细辛联合依帕司他对糖尿病肾病模型大鼠的治疗作用及机制

目的:探讨基于多元醇通路(PP)中醛糖还原酶(AR)灯盏细辛联合依帕司他(EPST)对糖尿病肾病(DN)大鼠氧化应激以及肾功能的干预机制。方法:将50只SD大鼠,随机平均分为正常对照组以及各干预组(模型组、EPST组、灯盏细辛组和EPST+灯盏细辛组)。各干预组采用单次注射链脲佐菌素(STZ)55 mg/kg合并喂养高脂高糖饲料的方法制备大鼠DN模型。持续灌胃给药6周后,观察大鼠一般形态学变化; HE染色观察大鼠肾组织形态变化; 血糖仪检测空腹血糖(FBG)水平; 动物体重天平检测体重水平; 全自动生化仪检测血肌酐(Scr)和尿素氮(BUN)水平; 试剂盒检测肾组织中超氧化物歧化酶(SOD)、丙二醛(MDA)、还原型谷胱甘肽(GSH)水平; ELISA检测24 h尿微量白蛋白(24 h UmAlb)和肾组织AR水平。结果:与正常对照组比较,模型组大鼠出现“三多一少”糖尿病典型症状,肾小球肥大,肾小管呈空泡样变性,FBG水平升高(P<0.01),体重水平降低(P<0.01),24 h UmAlb、Scr和BUN水平升高(P<0.01),SOD和GSH水平降低(P<0.01),MDA水平升高(P<0.01),AR活性升高(P<0.01)。与模型组比较,各给药组整体状态好转,肾组织病理结构损害显著降低,FBG水平降低(P<0.01),体重水平升高(P<0.01),24 h UmAlb、Scr和BUN水平降低(P<0.01),SOD和GSH水平升高(P<0.01),MDA水平降低(P<0.01),AR活性降低(P<0.01),而EPST+灯盏细辛组的作用显著优于EPST或灯盏细辛组(P<0.05)。结论:灯盏细辛与EPST联合给药能改善DN大鼠肾功能以及提高其抗氧化能力,且治疗效果优于单独给药组,其作用机制可能与通过下调肾组织AR活性来抑制PP的激活,并协同减轻肾组织氧化应激有关。     

A Meta-analysis of Trials on Aldose Reductase Inhibitors in Diabetic Peripheral Neuropathy

Peripheral neuropathy is one of the most common and disabling long-term seque lae of diabetes mellitus. Aldose reductase inhibitors (ARIs) have been proposed and are increasingly used in many countries for the prevention and treatment of diabetic neuropathy. The aim of this study was to review existing evidence on the effectiveness of ARIs in the treatment of peripheral diabetic neuropathy, with particular reference to the type and clinical relevance of the end point used and to the consistency of results across studies. Thirteen randomized clinical trials (RTCs) comparing ARIs with placebo, published between 1981 and 1993 were included in the meta-analysis. Nerve conduction velocity (NCV) was the only end point reported in all trials. Treatment effect was thus evaluated in terms of NCV mean difference in four different nerves: median motor, median sensory, peroneal motor, and sural sensory. A statistically significant reduction in decline of median motor NCV was present in the treated group as compared to the control group (mean 0.91 ms⁻¹; 95 % CI 0.41–1.42 ms⁻¹). For peroneal motor, median sensory, and sural sensory nerves results did not show any clear benefit for patients treated with ARIs. When the analysis was limited to trials with at least 1-year treatment duration, a significant effect was present for peroneal motor NCV (mean 1.24 ms⁻¹; 95 % CI 0.32–2.15 ms⁻¹) and a benefit of borderline statistical significance was also present for median motor NCV (mean 0.69 ms⁻¹; 95% CI −0.07−1.45 ms⁻¹). A heterogeneous picture emerged when looking at the results of different studies and serious inconsistencies were also present in the direction of treatment effects among nerves in the same studies. Although the results of 1-year treatment on motor NCV seem encouraging, the uncertainty about the reliability of the end-point employed and the short treatment duration do not allow any clear conclusion about the efficacy of ARIs in the treatment of peripheral diabetic neuropathy.     

石斛酚对醛糖还原酶的抑制作用及其机制研究

目的 探讨石斛酚对醛糖还原酶(AR)的抑制作用及其机制.方法 采用紫外分光光度法表征石斛酚对AR的抑制作用及抑制类型;采用分子对接软件Syby17.3中的FlexX预测二者作用残基及结合方式.结果 石斛酚对AR的IC50=2.12 mmnol/L,抑制类型为非竞争性抑制,并呈显强烈的量-效关系;二者作用残基为Trp111,His110,Tyr48,Trp20,主要结合方式是疏水相互作用、氢键和范得华力.结论 石斛酚对AR活性表现出良好的抑制作用.