大黄酚的抗衰老作用

目的:观察大黄酚对过氧化脂质(LPO)及脑胆碱酯酶(AChE)活性的影响。方法:采用分光光度法,体外实验测定大鼠肝、 脑组织中丙二醛(MDA)含量,体外实验及颈管内(icv)给药测定小鼠脑组织中AChE活性。结果:大黄酚可显著抑制大鼠肝、脑 LPO的生成,减少组织MDA含量,在体内、外均可显著抑制小鼠脑AChE活性,且有剂量相关性。结论:大黄酚具有抗衰老作用, 其作用机制与抑制LPO和AChE活性有关。     

冠心病患者血液流变学和氧化低密度脂蛋白变化及其相关性分析

目的 :观察冠心病患者血液流变学、氧化低密度脂蛋白、氧自由基变化及其相关性。方法 :择期开腹手术患者64例 ,冠心病组和对照组各 3 2例 ,同时监测血液流变学的变化、氧化低密度脂蛋白 （ox-L DL ）、脂质过氧化物（L PO）和超氧化物歧化酶 （SOD）等指标。结果 :冠心病组全血高切黏度、低切黏度、红血细胞压积、红细胞变形指数和 ox-L DL,均显著高于对照组 （P<0 .0 5或 P<0 .0 1） ;且全血高切黏度、低切黏度及红血细胞压积与 ox-L DL 间呈显著正相关 （P<0 .0 5） ;与对照组相比 ,冠心病组 L PO活性增高 （P<0 .0 5） ,SOD活性降低 （P<0 .0 5）。结论 :冠心病患者在血液流变学异常变化的同时 ,伴有 ox-L DL 和 L PO活性增高 ,SOD活性降低 ,且血液流变学变化与 ox-L DL间呈正相关     

Burn and Damage by Lipid Peroxidation

In this study,the plasma and erythrocyte(RBC)lipoperoxidation rates,the contents of antioxidant vitamin E(VE)and the activities of antioxidationenzyme SeGSHP_x of plasma and RBC in the patients with burn were determinedon the 1st,3rd,5th,10th and 15th days after burn.The results showed that ascompared with healthy subjects,the contents of Iipoperoxide were increased,and thelevels of VE and the activities of SeGSHP_x were decreased significantly.Thechanges became more significant with the time elapsing,and the most significantchanges were on the 10tb days postburn.In the meantime the percentages of RBCspontaneous hemolysis and the activities of SeGSHPx were increased,and thecontents of VE in RBC were decreased markedly.The regularity of the changes inthe lipoperoxidation rates of plasma and RBC was in accordance with that in thecontents of VE in them.The degrees of the changes in the LPO and VE contentsand the SeGSHPx activities in plasma were in relation to the extents of burn.Onthe 53th,65th and 85th days during recovery postburn,the changes were stillsignificant compared to the healthy subjects,although they had a tendency torestore.     

Protective effect of melatonin against adriamycin toxicity in the rat

Adriamycin, an anthracyclinic antibiotic frequently used in quimioterapeutic treatments is highly toxic; it inhibits protein synthesis and provokes prooxidant effects. Melatonin has recently been shown to have high antioxidative properties. We tested if melatonin is able to neutralize the oxidative damage induced by a single dose (20 mg/kg, i.p.) of adriamycin preceded (3 days) and followed (7 days) by a low pharmacological dose (50 microg/kg, i.p.) of melatonin. After the administration of a single dose of adriamycin (20 mg/kg i.p.) to male Wistar rats, the reduced to oxidized glutathione (GSH/GSSG) ratio and the glutathione peroxidase (GPx, E.C. 1.11.1.9.) activity in the brain, intestine, heart, kidney, and lung were significantly reduced. When the treatment of adriamycin was preceded and followed by low pharmacological doses of melatonin, the decrease in the GSH/GSSG ratio was significantly reduced but the reduction in GPx activity was not attenuated. A significant increase in lipid peroxidation products was observed in brain, heart, and kidney tissues after a single administration of adriamycin, which was attenuated by pre- and post-treatment with a low pharmacological dose of melatonin. Our results demonstrate that oxidative damage induced by the antitumor drug, adriamycin, can be reduced by low pharmacological doses of melatonin.     

脂质过氧化损伤对培养内皮细胞产生cAMP,一氧化氮的影响

目的：研究脂质过氧化损伤后内皮细胞产生环磷腺苷酸（ｃＡＭＰ）、一氧化氮（ＮＯ）的量的变化及ＮＯ形成过程中第二信使ｃＡＭＰ的作用。方法：用联胺、硒作为氧化剂及抗氧化剂,应用光镜、电镜、丙二醛测定方法观察内皮细胞脂质过氧化损伤程度;用放免方法测细胞内ｃＡＭＰ含量,Ｇｒｉｅｓｓ方法测培养液中ＮＯ代谢产物亚硝酸盐（ＮＯ－２）的含量。结果：联胺可以引起内皮细胞脂质过氧化损伤,低、中联胺浓度组ｃＡＭＰ含量明显升高,硒保护组比损伤组降低（Ｐ＜０．０１）,高联胺浓度组ｃＡＭＰ降低,加硒组有所回升（Ｐ＜０．０５）。但ＮＯ含量随联胺浓度升高增多（Ｐ＜０．０１）,硒可使ＮＯ升高程度减小（Ｐ＜０．０５）。ｃＡＭＰ升高因素可使内皮细胞（ＥＣ）产生ＮＯ增多。结论：轻中度或早期动脉硬化（ＡＳ）病变可能是通过ｃＡＭＰ介导的;ｃＡＭＰ可能在ＮＯ合成中起一定作用。以往ＮＯ“减少”的报道可能是由于产生的ＮＯ被自由基等灭活导致ＮＯ的活性降低     

血浆脂质过氧化物荧光测定

本文对血浆脂质过氧化物荧光测定法进行了初步探讨,制作了标准曲线及血浆用量曲线,测定了批内变异系数,选择了最适测定条件。结果批内变异系数5.56～5.71％,血浆用量在140μl之内与相对荧光强度呈很好线性关系,测定时选用100μl为宜。为了得到最大荧光强度,反应混合物与TBA试剂在95℃温育70分钟为适宜。最佳测定时间是取血即刻分离血浆,并进行测定或将血浆放于-30℃冰箱一周,再行测定,荧光强度不受影响。     

Aging changes of riboflavin concentration and glutathione reductase activity in erythrocytes

Aged erythrocytes obtained by fractionation using gradient centrifugation with Dextran 40, showed lower glutathione reductase activity and riboflavin content than young cells. However, both young and old cells displayed almost the same increase in enzyme activity upon addition of flavin adenine dinucleotide to the test hemolysate in vitro. The lipid peroxide content in the cell membranes showed no consistent changes with aging.     

荷瘤小鼠脂质过氧化与微量元素锰,锌的关系探讨

本文采用小鼠S_(180)移植性皮下肿瘤模型,在肿瘤生长的不同时间测定了肝脏及瘤组织的脂质过氧化水平及微量元素锰、锌含量。结果表明,随着肿瘤的生长,宿主肝脏及瘤组织脂质过氧化水平升高,锰的含量下降,两者呈负相关,瘤组织锌也呈下降趋势,但未显示出与脂质过氧化升高间的相关关系。提示,锰缺泛可能是造成脂质过氧化水平升高的原因之一。     

正常人血清过氧化脂质的水平

本文采用八木TBA荧光法测定了300名正常人血清过氧化脂质的含量,发现在儿童时期含量较低,随着年岭增长而升高,21岁到41岁各年龄组升高非常显著(p<0.01),从41岁到70岁各年龄组相对恒定(p>0.05),71岁以上含量减少。女性低于男性,但无明显差别(p>0.05)。300名正常人血清过氧化脂质含量平均值为2.84±0.75nmol/ml,正常值范围为4.31nmol/ml以下。     

烧伤与脂质过氧化损伤

本文观察了烧伤患者15天内血浆和RBC的脂质过氧化速率,VE含量和硒谷胱甘肽过氧酶SeGSHPx活性的变化.结果表明血浆脂质过氧化物LPO含量增加,VE含量和SeGSHPx活性降低,以伤后10天为最显著:RBC的自发性溶血百分率和SeGSHPx活性增加,RBC VE含量降低。血浆和RBC的脂质过氧化速率增加和它们的VE含量降低的变化规律相一致。血浆LPO和VE含量以及SeGSHPx活性变化幅度与烧伤严重度相关。