AC1及AC3对白内障形成中晶状体氧化还原物质及硒含量的变化

观察了AC1和AC3对抗亚硒酸钠性白内障形成过程中晶状体的脂类过氧化作用,非蛋白质疏基水平及硒含量。结果表明,亚硒酸钠组大鼠,在晶状体混浊出现前已发生脂类过氧化作用及硒含量的明显增加,非蛋白质巯基含量的显著降低,并持续至核混浊期;而同时接受AC1或AC3的大鼠,晶状体非蛋白质巯基水平初期降低,然后逐渐恢复至正常。AC1可有效的对抗亚硒酸钠所致的脂类过氧化作用增加,而AC3的对抗效应需一定剂量及时程,两者对晶状体硒含量均无明显影响。     

四种中草药对大鼠半乳糖性白内障氧化还原物质及糖类含量的影响

对正常和半乳糖性白内障及给中草药的大鼠晶状体中某些吡啶核苷酸成分、糖类、非蛋白质巯基的含量进行了比较。结果表明,在白内障晶状体中,NADPH及非蛋白质巯基的含量明显低于正常晶状体的,而NADP、半乳糖及半乳糖醇的含量明显高于正常晶状体的;当注射半乳糖的同时分别用黄岑、石斛、菟丝子及玉蝴蝶四种中草药水煎剂灌胃,上述变化为基本恢复至正常晶状体的水平。表明四种中草药对晶状体中的异常生化变化具有阻止及纠正作用。     

四种中草药成分对醛糖还原醇和脂类过氧化的抑制作用

我们在体外研究了四种中草药提取物对醛糖还原酶及脂类过氧化的抑制作用。结果表明,四种中草药的提取物在不同浓度下,对醛糖还原酶活性及脂类过氧化作用均有不同程度的抑制作用,其抑制醛糖还原酶活性的作用属非竞争性抑制类型。对醛糖还原酶活性及脂类过氧化的抑制作用均随中草药提取物浓度的降低而降低。本实验的结果证明中草药中含有抗脂类过氧化及抑制醛糖还原酶的某些成分。     

白内障形成过程中晶状体细胞膜上脂类与蛋白质氧化的时间差异性

用马来酰亚胺及５恶唑氮氧自由基硬脂酸分别标记晶状体细胞膜中蛋白质及脂类,以电子 自旋共振方法研究在三硝基甲苯、亚硒酸钠、半乳糖、平阳霉素及紫外线等白内障诱发剂作用下,晶状体细胞膜氧化损伤变化,结果发现当晶状体细胞暴露于空气中时,晶状体细胞膜脂类氧化早于蛋白质的氧化;在五种白内障诱发剂作用下,均是如此,这说明白内障的形成首先是由膜中脂类氧化所引起。     

白内障形成过程中晶状体细胞膜上脂类与蛋白质氧化的时间差异性

用马来酰亚胺及５恶唑氮氧自由基硬脂酸分别标记晶状体细胞膜中蛋白质及脂类,以电子自旋共振方法研究在三硝基甲苯、亚硒酸钠、半乳糖、平阳霉素及紫外线等白内障诱发剂作用下,晶状体细胞膜的氧化损伤变化。结果发现当晶状体细胞暴露于空气中时,晶状体细胞膜脂类氧化早于蛋白质的氧化;在五种白内障诱发剂作用下,均是如此．这说明白内障的形成首先是由膜中脂类氧化所引起。     

白内障形成过程中晶状体细胞膜上脂类与蛋白质氧化的时间差异性

用马来酰亚胺和５恶唑氮氧自由基硬脂酸分别标记晶状体细胞膜中蛋白质及脂类,以电子自旋共振方法研究在三硝基甲苯、亚硒酸钠,半乳糖、平阳霉素及紫外线等白内障诱发剂作用下,晶状体细胞膜的氧化损伤变化。结果发现当晶状体细胞暴露于空气中时,晶状体细胞膜脂类氧化早于蛋白质氧化;在五种白内障诱发剂作用下,均是如此。这说明白内障的形成首先是由膜中脂类氧化所引起。     

四氧嘧啶致大鼠糖尿病与脂类过氧化

四氧嘧啶致SD大白鼠糖尿病的过程中,首先引起体内多种组织器官广泛发生脂类过氧化作用。脂类过氧化物分解产生一些醛类物质,故血清、胰腺、肝和肾组织中TBA反应物(主要成分为丙二醛)含量升高;生成的其它醛类物质与蛋白质结合形成的水溶性荧光物质含量亦增多。抗氧化剂维生素E的抗脂类过氧化作用对机体起保护作用;而维生素C在大量氧化剂四氧嘧啶存在的条件下起氧化强化剂的作用,并使机体对维生素E的消耗增多。     

三硝基甲苯中毒性白内障动物模型的建立及其发病机理的初步研究

反复多次给大鼠皮下注射20％三硝基甲苯(TNT)甘油:水混悬液,染毒15个月后21％动物发生白内障,其裂隙灯检查结果与人TNT性白内障基本相似,同时注射甘油:水溶剂的对照组大鼠无一例发生白内障。染毒10个月的大鼠,其晶状体LPO增高,GSH-P_X及GST活性降低,GR活性无变化,而GSH含量明显增加;注射TNT后肝脏LPO值、GSH含量、GSH-P_X、GR及GST活性均明显增高。本文结果提示,TNT中毒性白内障的形成可能系TNT及其代谢产物直接作用于晶状体,造成昌状体氧化损伤所致。TNT白内障大鼠模型的建立亦为深入探讨其发病机理及防治奠定了基础。     

四种中草药对大鼠半乳糖性白内障相关酶活性的影响

本实验测定了中草药对大鼠半乳糖性白内障延缓及治疗中五种酶活性的影响。结果表明,在白内障晶状体中,醛糖还原酶的活性明显升高;多元醇脱氢酶,己糖激酶,6磷酸葡萄糖脱氢酶及过氧化氢酶的活性明显降低。在注射半乳糖的同时,分别用黄芩、石斛、菟絲子及玉蝴蝶四种中草药水煎剂灌胃,醛糖还原酶的活性没有明显升高,其余四种酶的活性均基本恢复到正常,表明这四种中草药对半乳糖所致的酶活性异常变化有抑制或纠正作用。     

脱氢表雄酮对大鼠脂类代谢和抗氧化作用的影响

目的：研究灌胃脱氢表雄酮（DHEA）对大鼠脂类代谢和抗氧化作用的影响。方法：选用健康雄性SD大鼠40只,随机分为4组（n=10）。对照组灌胃给予灭菌生理盐水,实验组灌胃给予20mg／kg、10mg／kg、5mg／kg体重的DHEA受试溶液,灌胃量均为1．5ml。每天一次,连续35d。实验结束后采血测定血糖（BG）、甘油三酯（TG）、总胆固醇（TO）、高密度脂蛋白胆固醇（HDL-C）、低密度脂蛋白胆固醇（LDL-C）,血清和肝脏超氧化物歧化酶（SOD）活性和丙二醛（MDA）含量。结果：DHEA显著降低大鼠血糖、TG、HDL-c及血清和肝脏MDA含量,显著升高血清LDL-c含量和肝脏SOD活性,而对大鼠体重、血清TC含量和SOD活性没有显著影响。结论：DHEA具有降低大鼠血脂和增强抗氧化能力的作用。     

Lipid peroxidation and cataract formation in experimental diabetes

To investigate the role of lipid peroxidation in diabetic cataractogenesis, malondialdehyde, a breakdown product of lipid peroxidation, was measured in lenses with incipient opacities and in retinas from diabetic rats and in clear lenses and in retinas from normal rats. The malondialdehyde mean values obtained in the transparent and cataractous lenses showed non-significant differences, while non-diabetic rat retinas had a significantly lower mean level of malondialdehyde compared with diabetic rat retinas (p less than 0.01). This indicates that, in streptozotocin-induced diabetic rats, lipid peroxidation is apparently not involved in the development of cataract, but it is quite probably involved in retinal damage. The retina, richer in polyunsaturated fatty acids than other ocular structures, is the elective site of lipid peroxidation and from this membrane peroxidation products might probably diffuse and damage other ocular tissues.     

The chemical nature of the fluorescing products accumulating in the lipids of the crystalline lenses of mice with hereditary cataract

The content of diene conjugates (lipid hydroperoxides) was shown to be significantly higher in lipids extracted from the lenses of mice with hereditary cataract than in the controls. The same holds true for characteristics of fluorescence of the end-product of lipid peroxidation. Two (low- and high-molecular weight) peaks were detected in chromatographic lipid profile of cataract lenses measured by fluorescence on Sephadex LH-20 column, whereas only one (high-molecular weight) peak was found in lipids from normal lenses. It was established that high-molecular weight fluorescent fractions corresponded to lipid components of lipofuscin-like pigments. NMR and mass spectrometry of low-molecular weight fractions suggested that they contained predominantly products of free radical oxidation of long chain polyunsaturated fatty acids (C22:6).     

Lipid fluorophores of the crystalline lens in cataracts

Microcolumn liquid and column chromatography technique is conjunction with UV-spectrophotometry and spectrofluorescent analysis were used to study lipid peroxidation products accumulated in human lenses during cataract formation by means of chromatographic separation in regard to the molecular weight and polarity properties. Cataract is characterized by the appearance of certain substances changing UV-absorption lipid spectra in the region of 230 and 274 nm and having special fluorescence (excitation--320-370 nm), (emission--405-460 nm). The same changes were observed by ultrasoundinduced lipid peroxidation of model lipid samples. The accumulated lipid peroxidation products are concentrated in the same chromatographic fractions that are responsible for the change of UV-absorption and fluorescent spectra of lipids of cataractous lenses. It is the evidence of free radical lipid peroxidation products accumulation in human lenses at cataract formation. Along with the formation of diene and triene conjugates in the lens lipids, cataract is characterized by the formation of cetodienes and of low molecular weight lipid fluorescent products of fatty acids oxidation with low polarity due to the appearance of tetraene derivatives of polyunsaturated fatty acids. The particular features of mature cataract are an increased intensity of long-wave lipid fluorescence in the blue-green region (430-460 nm) of the spectrum, formation of high molecular weight fluorescent lipid peroxidation products with high polarity, and smooth decrease in absorbance in the region of 220-330 nm. During cataract formation products of deep lipid peroxidation resulting from radical phospholipids and fatty acids polymerisation are accumulated. It is supposed that lipid peroxidation is an initial phase of membrane desintegration and formation of HMW-proteins in cataract.     

Age-related changes of lipid spectrum, level of lipid peroxidation, and antioxidant defence in the liver and blood of rats

It has been shown that the lowest level of total lipids, cholesterol, triacylglycerols and products of lipid peroxidation of blood and liver, as a rule, is specific to adult rats. These characteristics are significantly higher for old and young animals. At the same time, the level of glutathione and alphatocopherols in adults' liver is much higher than in young and old rats. It suggests the lower level of processes of lipid peroxidation in adult mature rats. The relative high level of products of lipid peroxidation and low content of alpha-tocopherols in old rats' liver (against the background of higher activity and glutamineperoxidase, and glutathionereductase than in adults) suggests tocopherol deficiency in old animals. High content of total lipids, cholesterol and cholesterol entering into the composition of lipoprotein of different density, triacylglycerols, diene conjugates and malonic dialdehide, activity of glutathione-dependent enzymes of antioxidant defence in young animals as compared with these levels in adult rats seems to be associated with agerelated hypercholesterolemia and intensive plastic changes of a growing organism.     

Lipid peroxidation in rat uterus

Lipid peroxidation in rat uterus has been studied using NADPH- and ascorbate-induced systems. Lipid peroxidation in rat uterus is low as compared to rat liver. Uterus is more sensitive to ascorbate-induced lipid peroxidation than that induced by NADPH. Uterus contains lower amounts of phospholipids and has a lesser degree of unsaturation in lipids. Co-factor studies show that Fe2+ is more important for ascorbate-induced lipid peroxidation. Endometrium is more sensitive to ascorbate-induced lipid peroxidation than myometrium. It also contains more total lipids and phospholipids besides having a higher degree of unsaturation in the lipids as compared to myometrium. Among the subcellular fractions, mitochondria are more prone to ascorbate-induced lipid peroxidation, whereas microsomes are more sensitive to NADPH-induced lipid peroxidation. Uteri from old rats (24 months) and pregnant rats are more resistant to lipid peroxidation than those from 3-month-old control rats. Uterus of pregnant rats contains more factors which inhibit lipid peroxidation and also has a lesser degree of unsaturation in lipids compared with uterus of control rats. The possible consequences of the resistance of uterus to lipid peroxidation, especially during pregnancy and senescence, are discussed.     

莲心碱对实验性高脂血症大鼠血脂及脂质过氧化的影响

本文研究莲心碱对实验性高脂血症大鼠血脂和抗氧化能力的影响.将32只大鼠随机分为4组,对照组饲喂基础饲料;诱导组饲喂高脂饲料;试验组给予高脂饲料+莲心碱灌胃2.5和5.0 mg·kg-1.测血清中血脂和丙二醛(MDA)水平,以及谷胱甘肽过氧化物酶(GSH-Px)、超氧化物歧化酶(SOD)活性;取肝脏测绝对和相对肝重及MDA含量.结果表明莲心碱可显著降低实验性高脂血症大鼠血清中总胆固醇、甘油三酯、低密度脂蛋白胆固醇水平和动脉粥样硬化指数;显著升高血清高密度脂蛋白胆固醇、GSH-Px和SOD水平;同时还可显著降低血清和肝脏中MDA的含量;其绝对和相对肝重均低于诱导组.     

Effects of Sterylglycosides from Soybean on Lipid Indices in the Plasma,Liver, and Feces of Rats

The effects of soybean oil (SOO, control), soybean lecithin (SOL), and of sterylglycocides (STG) and phospholipids (PL) fractionated from SOL on lipid indices in the plasma, liver, and feces were examined for male Wistar rats fed with diets containing these lipids for 3 weeks. The body weight gain and liver weight decreased or tended to be reduced in the animals given the diet containing a 5% STG mixture (STGM) compared with the values in the other dietary groups. The plasma lipid concentration in general declined in the rats fed with the diets supplemented with 5% SOL, STGM, or the PL mixture (PLM), and with 1% of STGM, acylated STG (ASTG), or non-acylated STG (NSTG). The triacylglycerol level was significantly depressed in the rats fed with the diets including 1 or 5% of STGM, ASTG, or NSTG when compared to the level of the SOO—fed animals. The total cholesterol and triacylglycerol contents in the liver were lower in the rats provided with the diets containing 5% of SOL, PC, or PLM than in the SOO- or STGM-diet-fed animals. The rats given the diets supplemented with 1 or 5% of STGM, ASTG, or NSTG had a decreased content of liver triacylglycerol compared with the content of the SOO—fed animals. The amounts of total lipids and total cholesterol excreted into the feces were higher in the rats fed with the diets supplemented with 5% SOL, or with 1% of STGM, ASTG, or NSTG, or especially with 5% STGM than in the SOO—fed animals. The present results suggest that STG suppressed the absorption of cholesterol and fatty acids in the intestines.