葡萄糖-6-磷酸脱氢酶测定方法及其与糖尿病和糖化血红蛋白关系的研究进展

糖尿病是严重危害人类健康的常见病、多发病。氧化应激损伤在糖尿病的发生和病理发展过程中起重要作用[1]。还原型谷胱甘肽(GSH)是体内的重要抗氧化物质,还原型辅酶Ⅱ(NADPH)和氢离子浓度(H+)对维持细胞中GSH的正常含量起重要作用。葡萄糖-6-磷酸脱氢酶(G-6-PD)是催化磷酸戊糖途径第一步的关键酶,其主要代谢产物是NADPH和H+。因此,研究G-6-PD与糖尿病发生和发展的关系近年来备受关     

红细胞-葡萄糖-6-磷酸脱氢酶活性水平与溶血的关系

目的分析红细胞-葡萄糖-6-磷酸脱氢酶(G-6-PD)活性与临床溶血程度的关系。方法采集在本院确诊为G-6-PD缺乏症患儿的临床资料,测定其红细胞-葡萄糖-6-磷酸脱氢酶活性,及其相关溶血证据,如:胆红素(TBIL)、游离血红蛋白(F-HB),对相关数据与G-6-PD活性进行关联性分析。结果在130例确诊患儿中,男122例,占93.85%(122/130),女8例,发病率6.15%(8/130),男性G-6-PD活性缺乏情况明显高于女性(P0.05);12例临床确诊的患儿黄疸指数正常,118例出现不同程度的黄疸,男性患黄疸数122例(93.85%),女性8例(6.15%),男性黄疸的发生几率明显高于女性(P0.05);G-6-PD与TBIL的关系:Logic回归分析显示,speaman值为0.099,P为0.366(P0.05),无统计学意义;G-6-PD与F-HB的关系:Logic回归分析显示,speaman值为0.129,P为0.296(P0.05),无统计学意义。结论蚕豆病患儿溶血与G-6-PD缺乏有关,但溶血程度G-6-PD活性高低无关。     

生化分析仪直接测定葡萄糖-6-磷酸脱氢酶活性的临床应用

葡萄糖-6-磷酸脱氢酶（glucose-6-phosphatedehy—drogenase，G-6-PD）是红细胞磷酸戊糖代谢途径中的一个关键酶，其催化反应生成的还原型辅酶Ⅱ（NADPH）是谷胱甘肽还原酶的辅酶，还原型谷胱甘肽（GSH）是保持血红蛋白稳定性及红细胞膜完整性的必要条件。红细胞G6-PD缺乏者，     

新生儿黄疸葡萄糖-6-磷酸脱氢酶活性检测及临床意义

目的通过新生儿葡萄糖-6-磷酸脱氢酶(G-6-PD)活性检测,了解耒阳地区新生儿黄疸患儿G-6-PD缺乏情况,为新生儿黄疸的临床诊断及治疗提供科学依据。方法对235例新生儿黄疸患者进行血浆G-6-PD活性测定。结果 235例新生儿中G-6-PD缺乏者4例,阳性率为1.7%。结论 G-6-PD缺乏为新生儿黄疸的重要原因,对G-6-PD缺乏的新生儿进行早期干预,能有效减轻G-6-PD缺乏,从而减轻新生儿溶血的程度,避免发生核黄疸。     

紫外分光光度法测定红细胞葡萄糖6磷酸脱氢酶活性的应用

红细胞代谢需多种酶参与，任何一种酶缺陷均可致溶血。其中主要有葡萄糖6磷酸脱氢酶（G-6-PD）和丙酮酸激酶（PK）缺陷。前者是G-6-PD催化反应生成的NADPH是谷胱甘肽还原酶的辅酶，还原型谷胱甘肽（GSH）是保持红细胞膜完整性的必要条件。红细胞G-6-PD缺乏引起NADPH生成减弱，进而导致GSH降低，使红细胞膜失去巯基的保护而功能受损终至溶血。后者导致糖酵解途径代谢障碍而引起溶血性贫血。G-6-PD酶活性定量测定作为诊断G6-PD酶缺乏的有效方法。     

葡萄糖-6-磷酸脱氢酶同工酶的琼脂糖凝胶电泳

测定红细胞葡萄糖-6-磷酸脱氢酶(G-6-PD)活性是诊断G-6-PD 缺乏的主要实验室检查指标。G-6-PD 的电泳特征是鉴定这种酶的重要变种的标准方法,且是诊断的重要依据。G-6-PD 同工酶的电泳已分别用于A 变种缺乏和女性杂合子缺陷的诊断。其同工酶鉴定已用于多数人群研究,亦用于父子血缘验证。作者报道了一种在载玻片上进行的改良琼脂糖凝胶电泳法,快速、价廉且图谱可永久保     

红细胞6-磷酸葡萄糖脱氢酶水平与血液学参数的关系

作者对175例贫血及非贫血病人,进行了红细胞6-磷酸葡萄糖脱氢酶(G-6-PD)和血液学参数的测定,并作了相关回归分析。结果经统计学处理发现红细胞G-6-PD活性与几个血液学参数具相关性。与血红蛋白(Hb)量、红细胞计数(RBC)、红细胞压积(Hct)呈负相关(P<0.0001),即G-6-PD活性随Hb、RBC、Hct的增加而降低。与白细胞计数(WBC)、平均红细胞体积(MCV)、网织红细胞数(RC)呈正相关(P<0.0001),与HBA_2、HbF、MCH、MCHC无相关性。根据上述实验结果,作者认为贫血患者如存在红细胞G-6-PD活性缺乏,受到Hb、RBC、PCV减少、网织红细胞和WBC增高尤其在感染时所掩蔽。红细胞G-6-PD活性增高的可能原因包括贫血病人网织红细     

用氰化抗坏血酸盐试验检测6-磷酸葡萄糖脱氢酶缺乏的女性杂合子

6-磷酸葡萄糖脱氢酶(G-6-PD)的研究,揭示了很多遗传变异体。其中活性降低及G-6-PD缺乏是男性最常见的遗传性代谢缺陷,全世界估计有一亿人患有此种病。决定此酶结构的基因载在X染色体上,因它是伴性不完全显性遗传。对男性仅有两种可能(即正常的和患病的),但对女性则有三种可能(即正常个体、纯合子、杂合子携带者)。她们通常不是中等酶水平,因为X染色体的不等失活。本文报告一种应用完整红细胞的氰化抗坏血酸盐试验,它可以把正常细胞与G-6-PD活性缺乏细胞区别开来。因此就能把多数G-6-PD缺乏的女性杂合子所带的正常细胞和异常细胞的混合群体显示出来。材料及方法取2毫升全血(EDTA抗凝),通气使成鲜红颜色,然后放入1支盛有10毫克抗坏血酸钠盐和5毫克葡萄糖的小试管中。再加入2滴     

自体回收血液红细胞2,3-DPG、G-6-PD、PS表达的变化研究

目的探讨血液回收对红细胞2,3-DPG和G-6-PD水平和磷脂酰丝氨酸（PS）表达的影响。方法选择心脏择期手术患者30例,使用费森尤斯盘式连续式血液回收机进行术中血液回收,与静脉血相比,比较红细胞2,3-DPG和G-6-PD水平和磷脂酰丝氨酸（PS）的表达变化。同时,将回收红细胞静置6h,比较上述指标的变化。结果与静脉血相比,放置0h的红细胞2,3-DPG与G-6-PD活性明显高于静脉血（P值均〈0.05）。流式细胞仪检测结果显示,两者红细胞膜PS表达的差异无统计学意义（P〉0.05）。放置6h的回收红细胞2,3-DPG活性明显低于静脉血（P〈0.01）,而G-6-PD活性与静脉血的差异无统计学意义（P〉0.05）。结论与静脉血相比,术中回收红细胞具有较好的携氧和抗氧化能力。但放置6h后的回收红细胞携氧能力不如静脉血。建议放置6h的回收红细胞不要回输。     

α-地中海贫血伴嘧啶5′-核苷酸酶缺乏患者的基因检测及其红细胞内酶活性变化

目的 探讨α-地中海贫血患者基因检测的临床意义,及其红细胞内嘧啶5′-核苷酸酶(P5′N)、丙酮酸激酶(PK)及葡萄糖-6-磷酸脱氢酶(G-6-PD)活性的变化.方法 选取就诊于我院的3例α-地中海贫血患者,用PCR-反向点杂交法和跨跃断裂位点PCR (gap-PCR)法进行基因分析,检测260、280 nm处吸光度(A)值,分析P5′N活性;用荧光斑点法检测PK和G-6-PD活性.结果 3例患者红细胞均呈小细胞低色素性,外周血涂片易见靶形红细胞及嗜碱性点彩红细胞.2例患者出现中度贫血,伴脾脏中度肿大、高胆红素血症及LDH升高,血红蛋白电泳可见一条快速带,血红蛋白醋酸纤维素薄膜电泳HbH含量明显升高;1例无症状患者未见上述异常.3例α-地中海贫血患者的基因型分别为(-α3.7/--SEA)、(ααQS/--SEA)和(--SEA),均存在P5′N活性降低,PK及G-6-PD活性未见异常.结论 α-地中海贫血可伴P5′N活性降低,基因检测对α-地中海贫血患者的诊断及其家系筛查具有重要临床价值.     

Clinical

Objective: To investigate the oxidative state of glutathione and glutathione peroxidase (GSH-Px'), glutathione reductase (GSSG-R), and glucose-6-phosphate dehydrogenase (G-6-PD) levels in patients with chronic renal failure (CRF) and controls.

Results: Erythrocyte GSH levels of patients were decreased, but GSSG was not significantly different from that of controls. Also, plasma GSH levels were not different, although GSSG was increased. GSSG/GSH ratios in erythrocyte and plasma were significantly higher in CRF patients. Erythrocyte GSSG-R activity was high, but G-6-PD and GPX were low.

Conclusions: The findings suggest that: 1. Low GSH is related to decreased G-6-PD activities. 2. The reduction of peroxides with GPX are decreased by low GSH and low GPX activity. 3. GSSG may react with hemoglobin and causes protein aggregation in erythrocytes. These alterations cause hemolysis and could play a role in the pathogenesis of anemia in hernodialyzed patients.     

Acetylsalicylic acid-induced hemolysis and its mechanism

Acetylsalicylic acid (ASA) is known to cause severe hemolytic anemia in some glucose-6-phosphate-dehydrogenase-deficient (G-6-PD-deficient) individuals. To study its mechanism, erythrocytes from an ASA-sensitive patient were transfused into a normal compatible recipient. The administration of 2,5-dihydroxybenzoic (gentisic) acid, a known ASA metabolite with redox properties, to the recipient resulted in a marked decrease in the survival of the patient's erythrocytes. Similar studies with red cells from individuals with A- and Mediterranean variants of G-6-PD revealed no alteration in the erythrocytes' survival. Further studies disclosed that both salicylate and gentisate competitively inhibited the G-6-PD from the ASA-sensitive patient resulting in a marked change in the K(m) for NADP. These drugs also inhibited the A- and Mediterranean variants of G-6-PD. The magnitude of inhibition, however, was comparatively small and not different from that observed with a normal enzyme.The above studies suggested that enzyme inhibition by salicylate and gentisate may play an important role in ASA-induced hemolysis. Such an inhibition would further curtail NADPH regeneration, rendering the cells more vulnerable to oxidants. In this connection, gentisate seems to play a major role in ASA-induced hemolysis for it is both a G-6-PD inhibitor and an "oxidant."     

Oxidative Stress and Antioxidative Status of Plasma and Erythrocytes in Patients with Vivax Malaria

Objectives: To investigate the oxidative stress and antioxidative status of plasma and erythrocytes in patients with vivax malaria and healthy persons.

Design and Methods: Activities of antioxidative enzymes, rates of pathways of hexose monophosphate shunt and purine salvage, levels of lipid peroxidation, reduced glutathione, methemoglobin and sulfhemoglobin of erythrocytes were determined. Lipid peroxidation and levels of antioxidant substances were measured.

Results: Antioxidants levels and antioxidative enzymes activities were lower and lipid peroxidation, purine salvage rate were higher in patients group than controls. Erythrocyte glucose-6 phosphate dehydrogenase (G-6-PD) activity was not different from that of healthy subjects.

Conclusions: Oxidative mechanisms were observed to be dominant compared with antioxidative mechanisms in patients with vivax malaria. Therefore, oxidative stress may be produced and maintained by the host defense mechanisms against malarial infection.     

Genetic diversity of the “Mediterranean” glucose-6-phosphate dehydrogenase deficiency phenotype

Genetic diversity of the "Mediterranean" phenotype of G-6-PD (glucose-6-phosphate dehydrogenase) deficiency was revealed when detailed studies were performed on blood specimens from 79 Greek males with G-6-PD levels 0-10% of normal. Four different mutants were found to be responsible for the severely deficient phenotypes: two mutants. G-6-PD U-M (Union-Markham) and G-6-PD Orchomenos, were distinguishable by electrophoresis, while the other two. G-6-PD Athens-like and G-6-PD Mediterranean, were distinguishable on the basis of their kinetic characteristics. Of the kinetic tests applied, the most useful for differentiating the variants were those measuring utilization rates of the analogue substrates deamino-NADP, 2-deoxyglucose-6-phosphate, and galactose-6-phosphate. Among unrelated males with severe G-6-PD deficiency, the relative frequencies of the four variants were: G-6-PD U-M. 5%; G-6-PD Orchomenos, 7%; G-6-PD Athens-like, 16%; G-6-PD Mediterranean, 72%. Genetic, biochemical, and clinical implications of the findings are discussed.     

Effect of pentylenetetrazol-induced epileptic seizure on the antioxidant enzyme activities, glutathione and lipid peroxidation levels in rat erythrocytes and liver tissues

OBJECTIVES: In order to clarify whether oxidative stress accompanies epilepsy, we examined the effects of pentylenetetrazol (PTZ)-induced epilepsy on the lipid peroxidation and antioxidant enzyme activities in erythrocytes and liver tissues of adult Wistar rats. MATERIALS AND METHODS: The activities of antioxidative enzymes (glucose-6-phosphate dehydrogenase (G-6-PD)), copper, zinc-superoxide dismutase (Cu,Zn-SOD), catalase (CAT), selenium-dependent glutathione peroxidase (Se-GSH-Px) and the levels of reduced glutathione (GSH) and thiobarbituric acid-reactive substances (TBARS) were measured in erythrocytes and liver tissues of pentylenetetrazol (PTZ)-induced epileptic adult Wistar rats. RESULTS: Single PTZ treatment in a convulsive dose of 50 mg/kg significantly reduced the erythrocyte Cu,Zn-SOD, CAT enzyme activities and GSH levels compared to controls (P < 0.001, P < 0.001, P < 0.05, respectively). Erythrocyte and liver tissue TBARS levels in the epileptic group were significantly higher than controls (P < 0.0001). There was a significant decrease in liver tissue Cu,Zn-SOD activity and GSH levels in the epileptic group (P < 0.0001), whereas significantly higher activities of G-6-PD and Se-GSH-Px were found in the epileptic group. CONCLUSIONS: Our results demonstrate a generalized diminished antioxidant activity and increased TBARS level indicating enhanced oxidative stress in the liver and erythrocytes of epileptic rats. Increased oxidative stress in the liver of epileptic rats might be due to the activation of the recently found glutamate receptors in the liver. These findings suggest that the use of antioxidants with antiepileptic drugs and new drugs such as type-5 metabotropic glutamate receptor (mGlu5) antagonist (MPEP) might protect erythrocytes and liver tissue against anoxic damage and oxidative stress.     

热休克蛋白90α、70、27mRNA在急性白血病细胞中表达的研究

运用RNA分子杂交的方法,观察了热休克蛋白(heat shock protein,HSP)90α、70、27在22例白血病病人细胞,正常血细胞及K562红白血病细胞系中的表达。结果表明:16例白血病病人中,4例急性淋巴细胞白血病(ALL),6例急性非淋巴白血病(ANLL)、1例慢性粒细胞白血病急变期(慢粒急变)和2例骨髓增生异常综合征(MDS)血细胞呈现HSP27高水平表达,较正常血细胞显著增多,ALL(5例)与ANLL(7例)白血病细胞HSP27表达水平无明显改变。检测了7例白血病细胞HSP70的表达水平,除1例ALL及1例MDS明显升高外,其余5例(包括1例ALL,3例ANLL和1例慢粒急变)显著低于正常血细胞。17例白血病病人细胞(包括9例ANLL、5例ALL、2例慢粒急变和1例MDS)HSP90α表达水平均升高,明显高于正常。结果提示:白血病细胞HSP90α表达水平的升高可能与白血病细胞活跃异常增殖有关,而HSP27基因的高表达可能不是某种急性白血病的特殊标志。     

Antioxidant capacity of G-6-PD-deficient erythrocytes

Glucose-6-phosphate dehydrogenase (G-6-PD) deficiency is the most common human enzymopathy. In this research, we studied two groups consisting of 30 male subjects who are G-6-PD deficient and 30 normal male subjects matched with the G-6-PD-deficient patients for age. All 30 assays were performed under normal conditions free of any oxidative attack that may result in haemolytic crisis in G-6-PD-deficient subjects. The erythrocyte glucose-6-phosphate dehydrogenase, superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), glutathione-S-transferase (GST) activities, reduced glutathione (GSH) levels and erythrocyte and plasma thiobarbituric acid-reactive substances (TBARS) levels were measured. All parameters in each group did not differ significantly except for G-6-PD levels. These data show that G-6-PD-deficient subjects can survive in normal conditions unless they are exposed to any oxidative stress.     

Characteristics and significance of the reverse glucose-6-phosphate dehydrogenase reaction

Glucose-6-phosphate dehydrogenase (G-6-PD) is the first enzyme of the hexose monophosphate pathway, and this important reaction is often considered to be irreversible. However, its apparent irreversibility is caused by the rapid removal of the immediate product, 6-phosphoglucono-delta-lactone. We have now investigated the reverse G-6-PD reaction, namely, the oxidation of reduced nicotinamide-adenine dinucleotide phosphate (NADPH) by 6-phosphoglucono-delta-lactone to form glucose-6-phosphate and nicotinamide-adenine dinucleotide phosphate (NADP). The substrate of the reaction, 6-phosphoglucono-delta-lactone, was rapidly generated from glucose-6-phosphate and NADP. The lactone was stabilized by addition of perchloric acid. A substrate analogue, 6-phosphoglucono-gamma-lactone, was synthesized by dehydrating 6-phosphogluconic acid. At pH 2.3 the t 1/2 of the delta-lactone was 2.4 hours; that of the gamma-lactone was 57 hours. The following kinetic parameters were established: Km delta-lactone 1027 +/- 183 mumol/L; Km gamma-lactone 266 +/- 71 mumol/L; Km NADPH less than 10 mumol/L; ratio of the Vmax G-6-PD forward/reverse reaction 2.0. Glucose-6-phosphate was found to be a competitive inhibitor with both lactones in the reverse G-6-PD reaction. Genetic mutants of humans in which the Km of G-6-PD for glucose-6-phosphate was diminished also had a diminished Km for 6-phosphoglucono-delta-lactone. Thus, it appears that the same active site on the enzyme binds glucose-6-phosphate in the forward reaction and 6-phosphogluconolactone in the reverse reaction.(ABSTRACT TRUNCATED AT 250 WORDS)     

四川遂宁地区献血者G-6-PD调查及进食蚕豆对蚕豆病儿输血的影响

应用改良四唑氮兰法对2483名献血者进行红细胞G-6-PD调查,G-6-PD缺乏率为8.3％,其中显著缺乏率为2.1％。建立献血者G-6-PD调查档案,防止蚕豆病儿输入缺乏G-6-PD的血液,提高了输血安全。观察献血者进食蚕豆后不同时间(2～4小时,12～24小时,2～3天)采血对蚕豆病儿输血的影响,各观察组临床症状与外周血Hb的恢复、G-6-PD活性的改变和对照组比较无明显差别,各组均未发现再溶血病例。提示蚕豆病儿在急性溶血后“不应期”内输入进食了蚕豆的献血者的血液无明显不良影响。     

Evaluation of glucose-6-phosphate dehydrogenase activity in two different ethnic groups using a kit employing the haemoglobin normalization procedure

AIM: Correct evaluation of Glucose-6-Phosphate Dehydrogenase (G-6-PD) activity of two ethnic groups using a fully quantitative kit with a simultaneous Hemoglobin Normalization (Hb Normalization) procedure. DESIGN AND METHODS: Two groups of mothers and their healthy full term newborns of Greek (n = 1.166) and Albanian (n = 818) origin were tested for their G-6-PD activity employing a direct normalization protocol. RESULTS: Greek mothers and newborns showed a higher prevalence for G-6-PD deficiency as compared to those of Albanian origin. Males of G-6-PD deficient mothers confirmed the efficacy of the method. CONCLUSION: A fully quantitative G-6-PD kit employing Hb Normalization is essential for the correct classification of G-6-PD activity, both in male and female subjects.