香烟烟雾对大鼠晶状体脂质过氧化与抗氧化作用的影响

目的观察香烟烟雾对大鼠晶状体的脂质过氧化作用以及对抗氧化酶活性和非蛋白质巯基的影响。方法将大鼠造成香烟烟雾损伤模型并测定晶状体中脂质过氧化产物丙二醛（ｍａｌｏｎｄｉａｌｄｅｈｙｄｅ，ＭＤＡ）和非蛋白质巯基（ｎｏｎ－ｐｒｏｔｅｉｎｓｕｌｐｈｙｄｒｙｌｇｒｏｕｐ，ＮＰ－ＳＨ）的水平以及超氧化物歧化酶（ｓｕｐｅｒｏｘｉｄｅｄｉｓｍｕｔａｓｅ，ＳＯＤ）和谷胱甘肽过氧化物酶（ｇｌｕ－ｔａｔｈｉｏｎｅｐｅｒｏｘｉｄａｓｅ，ＧＳＨ－Ｐｘ）的活性。结果吸烟组大鼠晶状体中ＭＤＡ含量明显增加（Ｐ＜０．０１），ＮＰ－ＳＨ的含量、ＳＯＤ和ＧＳＨ－Ｐｘ的活性均显著降低（Ｐ＜０．０１）。结论香烟烟雾可能是导致白内障形成的重要原因之一。     

晶状体谷胱甘肽的转运子研究

确定晶状体谷胱甘肽转运子的转性，检测白内障晶状体内该转运子的调节功能。方法有关ＧＳＨ转运的研究方法如下：（１）原位眼部血管灌注；（２）非洲爪蛙卵注射；（３）人晶状体上皮细胞培养。结果研究表明，晶状体对ＧＳＨ比对蔗糖的摄取要高几倍，同时还发现晶状体上皮比皮质摄取的速度要快得多。晶状体ｐｏｌｙ（Ａ）ＲＮＡ蛙卵注射对ＧＳＨ的摄取表达结果表明，晶状体上皮仅有一部分对Ｎａ具有依赖性。摄取显示出晶状体上对Ｎａ     

老年性白内障血房水晶体核中的抗氧化酶和抗氧化物相关性研究

探讨老年性白内障患者血,房水,晶体核中抗酶和抗氧化酶化物之间的相关关系及作用。方法随机取符合条件的老年性白内障４４例。超氧化物歧化酶（ｓｕｐｅｒｏｘｉｄｅｄｉｓｍｕｔａｓｅ,ＳＯＤ）用黄嘌呤氧化酶法测定,丙二醛（ｍａｌｏｎｄｉａｌｄｅｈｙｄｅ,ＭＤＡ）用巴比妥酸反应比色法测定,谷胱甘肽过氧化物（ｇｌｕｔａｔｉｏｎｅ－ｐｅｒｏｘｉｄｅ,ＧＳＨ－ＰＸ）用改进的还原型谷胱甘肽消耗法测定,ＶｉｔＣ和Ｖｉｔ     

正常犬血房水晶状体中的抗氧化酶和抗氧化物相关性研究

目的探讨正常犬血、房水、晶状体中抗氧化酶和抗氧化物在维持晶状体透明过程中的相关关系及作用。方法选用 ８～１２ ｋｇ健康成年杂种犬 ２０只，雌雄不限。超氧化物歧化酶（ＳＯＤ）用黄嘌呤氧化酶法测定，丙二醛（ＭＤＡ）用巴比妥酸反应比色法测定，谷胱甘肽过氧化物酶（ＧＳＨ－ＰＸ）用改进的还原型谷胱甘肽消耗法，ＶｉｔＣ和 ＶｉｔＥ分别用微量荧光法和比色法测定。结果ＳＯＤ，ＧＳＨ－ＰＸ，ＶｉｔＣ，ＶｉｔＥ及ＭＤＡ在血、房水、晶状体中相互间存在２６个明显相关方程（ｔ检验，Ｐ＜０．０１或Ｐ＜０．０５）。结论在正常情况下，在大血、房水、晶状体中抗氧化酶之间和抗氧化物之间以及二者之间存在相互协调、制约的动态平衡相关关系是保持晶状体透明的重要因素。     

老年性白内障血、房水、晶体核中抗氧化酶和抗氧化物研究

目的：了解抗氧化酶和抗氧化物之间的关系及其在老年性白内障形成中的作用。方法：随机取符合条件的老年性白内障４４例（４４眼）,男２３例,妇女１例,平均年龄６７．７岁。用黄嘌呤氧化酶法测定超氧化物歧化酶（Ｓｕｐｅｒｏｘｉｄｅ ｄｉｓｍｕｔａｓｅ,ＳＯＤ）、丙二醛（Ｍａｌｏｎｄｉａｌｄｅｈｙｄｅ ＭＤＡ）用巴比妥酸反应比色法测定,谷胱甘肽过氧化物酶（Ｇｌｕｔａｔｈｉｏｎｅ－Ｐｅｒｏｘｉｄｅ,ＧＳＨ－ＰＸ）     

晶状体与谷胱甘肽的研究进展

白内障是我国目前主要的致盲性疾病之一,而日益受到眼科工作者的重视。谷胱甘肽（ＧＳＨ）对控制白内障的发生具有重要意义。在哺乳动物体内,晶状体是富含ＧＳＨ的组织。它的存在对维持晶状体的透明起着非常重要的作用。就ＧＳＨ在晶状体内的合成、分布、代谢及其功能等最新的研究状况作一综述。     

外源性SOD对兔急性高眼压致视网膜损伤保护作用的研究

目的探讨高眼压后活性氧自由基对视网膜组织的损伤情况及外源性超氧化物歧化酶（ｓｕｐｅｒｏｘｉｄｅｄｉｓｍｕｔａｓｅ,ＳＯＤ）对高眼压致视网膜损伤的保护作用。方法观察６．６７ｋＰａ（１ｋＰａ＝７．５ｍｍＨｇ）、维持１．５ｈ的高眼压解除２４ｈ内兔视网膜组织中脂质过氧化产物丙二醛（ｍａｌｏｎｄｉａｌｄｅｈｙｄｅ,ＭＤＡ）含量、ＳＯＤ活性、谷胱甘肽过氧化物酶（ｇｌｕｔａｔｈｉｏｎｅｐｅｒｏｘｉｄａｓｅ,ＧＳＨ－Ｐｘ）活性和还原型谷胱甘肽（ＧＳＨ）含量的变化情况及球后注射Ｃｕ－Ｚｎ－ＳＯＤ对高眼压解除后１２ｈ时兔视网膜组织中ＭＤＡ含量和ＳＯＤ活性的影响。结果ＭＤＡ在高眼压解除后０～１２ｈ逐渐增加,１２～２４ｈ维持较高水平。ＳＯＤ活性和ＧＳＨ－Ｐｘ活性在高眼压解除即刻均低于正常水平,以后有不同程度增高,其中ＳＯＤ活性在高眼压解除４ｈ后又开始下降。ＧＳＨ在高眼压解除后２４ｈ内无明显变化。球后注射Ｃｕ－Ｚｎ－ＳＯＤ能减少兔视网膜组织中ＭＤＡ生成,增加ＳＯＤ活性。结论活性氧自由基参与了高眼压致视网膜损伤,球后注射大剂量ＳＯＤ对提高视网膜抗氧化损伤能力有积极意义。     

老年性白内障的氧化损伤与酶组织化学观察

目的 研究老年性白内障晶状体上皮酶活性变化和氧化损伤对培养的牛晶状体上皮细胞酶活性的影响。方法 １．取老年性白内障晶状体和正常透明晶状体进行酶组织化学染色,观察ＳＤＨ,ＬＤＨ,Ｇ６ＰＤ,ＡＴＰａｓｅ活性的变化。２．观察培养牛晶状体上皮细胞氧化损伤后及维生素Ｃ治疗后ＳＤＨ,ＬＤＨ,Ｇ６ＰＤ活性的改变。结果 １．老年性白内障ＳＤＨ,ＬＤＨ,Ｇ６ＰＤ,ＡＴＰａｓｅ活性降低。２．培养的牛晶状体上皮细胞经过氧化损伤后ＳＤＨ,ＬＤＨ,Ｇ６ＰＤ活性显著降低,维生素Ｃ可使酶活性显著提高。结论 氧化损伤使能量产生减少,可能是白内障发生的原因之一,维生素Ｃ对氧化损伤具有部分保护作用。     

碱性成纤维细胞生长因子对牛晶状体上皮细胞增殖的影响及其在牛晶 …

目的 研究碱性成纤维细胞生长因子（bＦＧＦ）在体外对牛晶状体上皮细胞（ＢＬＥＣ） 增殖的影响及确定ＢＬＥＣ是否表达bＦＧＦ蛋白。方法 ＢＬＥＣ原代培养。用不同浓度的bＦＧＦ及＾３Ｈ－胸腺嘧啶（＾３Ｈ－ＴＤＲ）处理ＢＬＥＣ３６h后,液闪测定bＦＧＦ对ＢＬＥＣ＾３Ｈ－ＴＤＲ掺入率的。Ｗｅｓｔｅｎ印迹（Ｗｅｓｔｅｎ ｂｌｏｔ）法确 定ＢＬＥＣ是否表达bＦＧＦ蛋白。结果 bＦＧＦ在体外有促进ＢＬＥＣ增殖作用,Ｗｅｓ     

单纯疱疹性角膜炎发病机制研究的新进展

单纯疱疹性角膜炎（ｈｅｒｐｅｓｓｉｍｐｌｅｘｋｅｒａｔｉｔｉｓ，ＨＳＫ）是主要的致盲眼病之一，主要由单纯疱疹病毒Ⅰ型（ＨＳＶ－Ⅰ）感染眼部引起。近１个世纪以来，有关ＨＳＶ－Ⅰ眼部感染的研究吸引着众多的科学家。早在１８７３年，人们就认识到ＨＳＶ－Ⅰ是导致眼部感染的致病因素之一，Ｇｕｎｔｅｒ和Ｌｏｗｅｎｓｔｅｉｎ曾经推测ＨＳＶ－Ⅰ感染很可能与中枢神经系统有关，自从１９７１年首次通过器官培养从潜伏感染的三叉神经节（ｔｒｉｇｅｍｉｎａｌｇａｎｇｌｉｏｎ，ＴＧ）中分离出ＨＳＶ－Ⅰ之后，人们正在运用各种技术对ＨＳＫ的发病机制尤其是ＨＳＶ－Ⅰ在感觉神经和中枢神经系统中的潜伏状态和复发机制进行研究和说明。对有关的研究进行综述，供参考。     

Cleavage of lens protein-GSH mixed disulfide by glutathione reductase

Mixed disulfide complexing the bovine lens erystallins and GSH was prepared by incubating the soluble proteins with GSSG. GSH could be released from the mixed disulfide in the presence of NADPH or NADH. Mixed disulfide was purified using DEAE-Sephadex A-50 column chromatography and was found to be free of glutathione reductase. In such preparation of mixed disulfide NADPH failed to release GSH. However, addition of glutathione reductase along with NADPH released substantial amounts of GSH from the mixed disulfide. Bovine serum albumins also form mixed disulfide with GSH and the mixed disulfide could be cleaved by glutathione reductase. Alkylation of protein sulfhydryl groups by N-ethylmaleimide prior to the addition of GSSG for the preparation of mixed disulfide, almost completely prevents the formation of mixed disulfide indicating that the formation of mixed disulfide involves protein sulfhydryl groups. Evidence is presented that the cleavage of mixed disulfide is not mediated by GSH with cyclic reduction of GSSG by glutathione reductase, but rather proceeds enzymically through glutathione reductase.Using the borohydride method, small amounts of GSH were found to be bound to normal human lens proteins and a substantial amount of GSH was found to be bound to lens proteins from senile cataracts. Only a very small amount of GSH was bound to bovine lens proteins. Glutathione reductase failed to release a significant amount of GSH bound to lens proteins in human cataractous and normal lens. The significantly greater increase in the protein thiols after the borohydride treatment of lens proteins from normal and cataractous human lens and from bovine lens cannot be accounted for by release of GSH bound to proteins. This indicates significant intramolecular and/or intermolecular disulfide bridges in lens proteins.     

平阳霉素体外诱发大鼠白内障的早期生化变化

目的和方法：用器官培养的方法在培养基中加入一定剂量的平阳霉素作用于大鼠晶体而诱发形成白内障,并在白内障形成的早期过程中观察了晶体内非蛋白质巯基,蛋白质巯基和二硫键同仁以及脂类过氧化水平的动态变化。结果和结论;培养１０ｍｉｎ时,非蛋白质巯基首先下降;随后蛋白质巯基含量也开始降低;二硫键的含量至４０ｍｉｎ时才呈现升高的趋势;而ＭＤＡ在培养的３０ｍｉｎ后明显升高。     

Role of lipid peroxidation in the pathogenesis of myopic and senile cataract.

AIMS/BACKGROUND: Increased production of free radicals, consumption of antioxidant, and oxidation of unsaturated lipids have been observed recently in cataractous lenses and active participation of the retina in human cataractogenesis has been proposed. To verify this hypothesis, the total (GSH) and oxidised (GSSG) glutathione concentrations were assayed in the lens and the malondialdehyde (MDA) levels assayed in the vitreous and in the lens of normal controls and patients with senile or myopic cataract. METHODS: The study was conducted on 34 lenses (nucleus and epinucleus) (nine clear lenses, 14 lenses with idiopathic senile cataract, and 11 lenses affected by severe myopic cataract) and vitreous of 19 (seven non-myopic, seven myopic, and five control) subjects. Glutathione determination was performed following the method of Reed, while malondialdehyde was assayed using a modification of the method of Dahle. RESULTS: Cataractous lenses showed a decreased content of GSH and increased concentration of GSSG compared with clear lenses. A higher oxidative consumption of GSH was found in myopic cataracts compared with senile ones. Also, increased levels of MDA were observed both in cataractous lenses and in the vitreous of myopic patients compared with the control and the senile ones. CONCLUSION: The observed alterations strongly suggest that retinal lipid peroxidation might play a key role in human cataractogenesis, especially in the myopic type.     

Role of glycosylation in protein disulfide formation and cataractogenesis

In order to study if glycosylation plays a role in the formation of protein disulfides and cataractogenesis, the levels of total sulfhydryl, GSH, protein disulfides (PSSP), protein mixed disulfide (PSSG) and the extent of glycosylation has been determined in normal, senile cataractous and diabetic cataractous lenses. No correlation between the extent of glycosylation and the total disulfide, PSSP or PSSG was observed in the normal, senile cataractous or diabetic cataractous lenses. This indicated that glycosylation probably does not play a primary role in cataract formation in diabetic patients.     

A Raman study of disulfide and sulfhydryl in the Emory mouse cataract

Emory mice (EM) are genetically predisposed to late-onset cataract formation. Our early work has shown UV-exposure slightly enhanced the expected 2 SH----SS conversion of normal mouse lenses only in the cortical regions. There was essentially no difference in the disulfide profiles of the nuclear region between UV-exposed and control lenses. Since the first noticeable change in the Emory mouse is a hazy nucleus when a lens is examined in vitro, we wondered if cataractogenesis in this model is different from the UV-produced cataract. This question was answered by comparing the visual axis profiles for SH and SS in early EM cataracts and in clear lenses from age-matched controls. The sulfhydryl profiles show that the SH level of 8.5-month-old EM lenses is essentially the same as that of the controls. Likewise, the disulfide profiles show no significant difference. The results clearly demonstrate that EM lenses do not undergo accelerated disulfide production. Therefore for the EM lens, the early stage of cataract formation must involve factors other than just accelerated oxidation of protein SH or glutathione SH. Invest Ophthalmol Vis Sci 29:823-826, 1988     

Preventive effect of danshensu on selenite‐induced cataractogenesis in cultured rat lens

Background: To investigate the preventive effect of danshensu on the selenite‐induced opacification of cultured rat lenses. Methods: Isolated lens were divided into three groups with eight lenses in each group. Group I: lenses were incubated with M199 medium alone; Group II: incubated in M199 containing 200 µmol/L sodium selenite; Group III: incubated in M199 containing 200 µmol/L sodium selenite and 500 µmol/L danshensu. Selenite was administered on the third day, and danshensu treatment was from the second to the fifth day. Cataracts development was observed using an inverted microscope, and the lenses were analysed for total anti‐oxidative capabilities, mean activities of superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase and glutathione S‐transferase; levels of reduced glutathione; malondialdehyde; and total sulfhydryl content. Results: All lenses in Group I were clear, whereas all lenses in Group II developed dense vacuolization and opacification. In Group III, 25% lenses revealed minimal vacuolization, and 75% showed no opacification or vacuolization. Total anti‐oxidative capabilities and the mean activities of anti‐oxidant enzymes superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase and glutathione S‐transferase; levels of glutathione; and total sulfhydryl content were elevated, and the level of malondialdehyde was decreased following treatment with danshensu compared with Group II. Conlusion: The anti‐oxidative properties of danshensu may play a major role in its contribution to the anticataract effect.     

Systemic human diseases as oxidative risk factors in cataractogenesis. II. Chronic renal failure

In this study we have investigated the oxidative metabolism of red cells (RBC), plasma, serum and aqueous humour of healthy subjects and of age-matched cataractous patients with and without chronic renal failure (CRF). Reduced glutathione (GSH) levels in RBC were lower in CRF patients than in the other groups. Oxidized glutathione (GSSG) plasma levels in CRF patients were higher than those of controls and cataractous subjects. The activity of the enzyme glucose-6-phosphate dehydrogenase in RBC was significantly reduced in CRF patients with respect to the other two groups. The levels of malondialdehyde (MDA) in RBC and in lens were about twice in CRF patients compared with the other two groups. The plasma levels of vitamin E were diminished in CRF patients; on the contrary, the biological liquid oxidant activity (BLOA) of serum in CRF patients was significantly higher than in controls and in cataractous patients without CRF. Cataractous patients with and without CRF showed similar levels of GSH in aqueous humour; on the contrary, the content of GSSG was significantly higher in CRF patients. Our findings seem to demonstrate that CRF patients are exposed to oxidative stresses that could probably act synergistically with uraemia and carbamylation of lens proteins. This synergism could explain why CRF represents a relatively high risk factor for cataract.     

The effect of resveratrol in experimental cataract model formed by sodium selenite

PURPOSE: To investigate if resveratrol can prevent sodium selenite-induced experimental cataract model in rats. METHODS: Forty-eight Spraque-Dawley rat pups were divided into 3 treatment groups: (1) normal saline-% 5 ethanol injected i.p. on postpatum day 10; (2) Na selenite (30 nmol/g body wt) injected s.c on day 10; (3) Na selenite s.c on day 10+resveratrol (40 mg/kg) i.p on days 10-13. On day 21, cataract development was graded by slit-lamp examination and photography. Encapsulated lenses and erythrocytes were analyzed for reduced glutathione (GSH) and malondialdehyde (MDA), a marker of lipid peroxidation. Lenses were also analyzed for total nitrite (TN). RESULTS: All control lenses in group 1 were clear. In group 2, all rats developed cataracts (grade 3-grade 6), whereas in group 3, only 9 of 16 rats developed cataracts (grade 2-grade 3). The difference of cataract frequency between groups 2 and 3 was statistically significant (p<0.05). Group 3 lenses and erythrocytes had higher mean GSH and lower mean MDA levels than those in group 2 (p<0.05). TN was highest in group 3 and lowest in group 1 (p<0.05). CONCLUSIONS: Resveratrol suppressed selenite-induced oxidative stress and cataract formation in rats. This protective effect was supported by higher GSH and lower MDA in lens and erythrocytes. The presence of oxidative stress in selenite cataract development and its prevention by resveratrol support the possibility that high natural consumption of resveratrol in food can help prevent human senile cataract.     

Blood and lens lipid peroxidation and antioxidant status in normal individuals,senile and diabetic cataractous patients

PURPOSE: Oxidative mechanisms are believed to play an important role in the pathogenesis of cataract, the most important cause of visual impairment at advanced age. To determine the body's antioxidant status as well as its lipid peroxidation levels, both blood and lens parameters were evaluated. METHODS: This study was performed on the blood samples and lenses obtained from 46 patients diagnosed as having cataract and 20 control subjects. The control group was composed of 10 women and 10 men who do not smoke. Control subjects without any lens opacity or vacuoles when observed with a slit lamp were recruited on the same exclusion criteria as far as disease and treatment were concerned. No antioxidant medicines were used. They were all healthy individuals without any systemic diseases. Superoxide dismutase (SOD), glucose-6-phosphate dehydrogenase (G6PD), glutathione reductase (GSSG-Red) activities in red blood cell (RBC) lysates as well as whole blood glutathione (GSH) and plasma thiobarbituric acid reactive substances (TBARS), the indicator of lipid peroxidation concentrations, were determined quantitatively both in the blood samples and the lenses of the patients with senile and diabetic cataracts. RESULTS: Whole blood GSH values, and erythrocyte SOD activities were significantly lower in the cataractous patients than those in the control group. The values in the diabetic cataractous group were also less than those in the senile cataractous group. Significantly decreased erythrocyte GSSG-Red and G6PD activities were detected in the diabetic cataractous group. Plasma TBARS values were higher both in the senile and diabetic groups when compared to those in the control group. Significantly decreased values were observed for GSSG-Red activities and TBARS values in the lenses of the senile cataractous patients in comparison with those in the diabetic cataractous patients. The lens GSH values were found to be higher in the senile cataractous group than the values obtained in the diabetic cataractous group. CONCLUSIONS: A strong correlation was found between lens GSH and lens TBARS concentrations in the diabetic group. This emphasized the vital role of GSH as an antioxidant in the lens over the other antioxidant parameters, e.g., enzymes, and the oxidative stress is at the highest level in lens.     

Exposure of rabbit lens to hyperbaric oxygen in vitro: regional effects on GSH level

Previous studies have indicated that in vivo exposure to hyperbaric O2 may be associated with the development of nuclear cataract. In the present work, in vitro effects of hyperbaric O2 on rabbit lenses were investigated following culture of the lenses in an atmosphere of 99% O2 at pressures ranging between 1 and 100 atm. Treatment with O2 resulted in a significant decrease in the level of reduced glutathione (GSH) in the lenses even at the lower pressures studied (less than 8 atm). At 100 atm O2 the loss of GSH was 85% after a 3 hr exposure. At 8 atm O2 a significant drop in GSH concentration was shown to occur in the lens nucleus prior to loss of the tripeptide in the superficial cortex. O2-treated lenses became hazy in appearance, especially at the higher pressures, but did not become densely opaque. Pressures of N2 up to 100 atm had no effect on either lens transparency or on the concentration of GSH. Although oxidized glutathione (GSSG) was detected in the whole lens at pressures of O2 as low as 4 atm, no change in GSH level or evidence for GSSG accumulation was observed in the capsule-epithelium of the lens at pressures as high as 50 atm O2. Ninety percent of the GSSG present in lenses after exposure to 100 atm O2 could be reconverted to GSH by subsequent culture of the lenses under normal conditions. Exposure of lenses to 50 atm O2 produced a three-fold stimulation of hexose monophosphate shunt activity, equal to that which has been reported for treatment of lenses with 0.06 mM H2O2.(ABSTRACT TRUNCATED AT 250 WORDS)