大黄对小鼠肝脏脂质过氧化的抑制作用

大黄水提物和醇提物对小鼠离体肝脏体外培养过氧化脂质（ＬＰＯ）生成均有明显的抑制作用；大黄水提物可明显抑制阿霉素肝损伤和Ｄ－半乳糖亚急性衰老模型小鼠肝脏ＬＰＯ的升高。     

人体血清过氧化脂质、抗氧化酶、铜、锌及硒与增龄的关系

观察6～82岁健康男性217人的血清过氧化脂质(LPO)及血抗氧化酶、Cu、Zn、Se与增龄的关系发现,由儿童期进入少年期,LPO即开始增加,老年前期,LPO又增,60岁以上增至最高。儿童期至老年前期,红细胞超氧化物歧化酶(SOD)及血谷胱甘肽过氧化物酶(GSH-Px)一直较稳定。老年期明显下降。Zn、Cu及Zn/Cu水平儿童期最高,青、中年及老年前期波动不大,老年期最低。未观察到各年龄组的血硒含量有显著差异。单相关分析:年龄与LPO呈正相关,与GSH-Px呈负相关,与血Zn/Cu呈负相关。逐步回归分析发现,与年龄关系最密切的是LPO及GSH-Px。提示,LPD似可作为老化的一种指标。如能注意营养,调节体内Cu、Zn水平,增强抗氧化酶活力,可能有助于抑制自由基反应,延缓衰老。     

乳鸽和蛇提取液延缓衰老的实验研究

黄蛸蛇有活血通络、强筋壮骨作用,乳鸽肉补五脏,可益中续气[1,2],是广西民族传统的滋补食疗配伍原料,为进一步发掘地方药食两用动物资源,我们用黄蛸蛇和乳鸽提取液进行延缓衰老作用的实验研究,用现代医学理论探讨其对老年保健作用机制。1　材　料　与　方　法1.1　原料与制备　　乳鸽和黄蛸蛇均购自市场,不放血宰杀后去皮毛和内脏,洗净后隔水蒸熟,拆去骨骼,按1∶10加水匀浆,酶解后过滤,收集滤液浓缩后备用,浓缩体积50%。1.2　实验方法1.2.1　用同一批24小时内羽化的美国野生型黑腹果蝇成虫(Drosophiliamelangaster)经乙醚麻醉后,区分雌雄并…     

Developmental pattern of reactive oxygen species generation and antioxidative defense machinery in rat cerebral microvessels

The developmental profile of certain enzymatic antioxidants as well as the generation of reactive oxygen species was studied in the rat cerebral microvessels during first three weeks of life and the levels were compared to those present in adults. The data showed a higher generation of superoxide anion (+67%) and H2O2 (+200%) at postnatal day (PND) 21. Superoxide anion production was significantly lower (-24%) at PND 14 and almost comparable to adult values at PND 7. The activity of superoxide dismutase increased with development and attained an adult level at PND 21. Catalase was higher in neonates with a maximum activity at PND 7 and 14 (+68, 69%). The measurement of microvessel glutathione and glutathione-related antioxidant enzymes showed that glutathione level was higher at PND 7, which declined to an adult level at PND 14. Se-dependent GPx showed a marked increase between PND 14 and 21, however, it declined in adults. The activity of Se-independent glutathione peroxidase was very low in cerebral microvessels. Glutathione reductase activity in 7-day-old, that was comparable to adult level, declined at PND 14 and 21. The level of glutathione S-transferase was higher (+43%) at PND 21. The activity of microvessel marker enzyme gamma-glutatmyl transpeptidase increased with age, whereas, alkaline phosphatase showed a slight increase up to PND 14 and thereafter it declined. Lipid peroxidation was found to be significantly lower (-18%) at PND 21 as compared to adults. It may be concluded that developing cerebral microvessels contain high levels of several antioxidant enzymes that are more or equal to those present in adult brain microvessels.     

Coronary endothelial dysfunction in the insulin-resistant state is linked to abnormal pteridine metabolism and vascular oxidative stress

OBJECTIVES

We investigated whether abnormal pteridine metabolism is related to coronary endothelial dysfunction in insulin-resistant subjects.

BACKGROUND

Depletion of tetrahydrobiopterin (BH₄) and elevation of the 7,8-dihydrobiopterin (BH₂) (activating and inactivating cofactors of nitric oxide synthase [NOS], respectively) contribute to impairment of NO-dependent vasodilation through reduction of NOS activity as well as increased superoxide anion generation in insulin-resistant rats.

METHODS

Thirty-six consecutive nondiabetic, normotensive and nonobese subjects with angiographically normal coronary vessels were studied. Traditional coronary risk factors, plasma pteridine levels, activities of erythrocyte dihydropteridine reductase (DHPR), the recycling enzyme that converts BH₂ to BH₄ and lipid peroxide (LPO) levels were measured and coronary endothelial function was assessed with graded infusions of acetylcholine (ACh).

RESULTS

When we divided patients into tertiles based on insulin sensitivity, we observed stepwise decreases in the maximal ACh-induced vasodilation and plasma BH₄/7,8-BH₂ ratio, and increases in coronary LPO production as insulin sensitivity decreased. The ACh-induced vasodilation was positively correlated with insulin sensitivity, BH₄/7,8-BH₂ ratio and DHPR activity. Furthermore, BH₄/7,8-BH₂ was inversely correlated with DHPR activity and insulin sensitivity. In multiple stepwise regression analysis, BH₄/BH₂ was independently related to ACh-induced vasodilation and accounted for 39% of the variance. However, no significant correlation existed between other traditional risk factors and BH₄/7,8-BH₂.

CONCLUSIONS

These results indicate that both abnormal pteridine metabolism and vascular oxidative stress are linked to coronary endothelial dysfunction in the insulin-resistant subjects.     

冠心病心力衰竭时氧自由基对心肌损伤的研究

目的探讨氧自由基在心衰时对心肌的损伤。方法对52例冠心病患者心衰时血浆过氧化脂质(P-LPO)、红细胞过氧化脂质(Ery-LPO)、血浆超氧化物歧化酶(P-SODA)、红细胞超氧化物歧化酶(Ery-SODA)活性进行测定,并与46例冠心病无心力衰竭患者及正常对照者之间作比较分析。结果冠心病心力衰竭患者LPO明显升高(P<0.01),SODA活性显著下降(P<0.01),其变化且随心力衰竭程度加重而更加显著;心力衰竭纠正后,LPO逐渐下降,SODA显著回升。结论氧自由基不仅参与心力衰竭的病理生理过程,而且也可作为判断病情轻重的参考指标。     

红景天甙抗二倍体细胞衰老的实验研究

目的 观察红景天甙对人胚肺二倍体成纤维细胞的抗老化作用。方法 在培养的二倍体细胞营养液中加入适量的红景天甙,待细胞传至10代后,检测二倍体细胞内SOD活性及LPO含量。结果 实验组二倍体细胞内SOD活性明显高于对照组（P＜0．01）,而LPO含量实验组低于对照组（P＜0．05）。结论 红景天甙可显著提高二倍细胞中SOD活性,降低LPO含量,延长二倍体细胞的老化。     

西比灵对大鼠急性脑缺血再灌注损伤保护作用的实验研究

一步探讨西比灵对急性脑缺血再灌注损伤的保护作用机制。方法　采用Pulsinelli四血管闭塞法制备大鼠急性脑缺血再灌注模型 ,利用Tsuchida的WSPS法测定LPO ,利用化学发光法测定SOD活性 ,同时观察了脑组织水含量及病理变化 ,并观察西比灵对上述指标影响。结果　①脑缺血后脑组织水含量升高 ,再灌注后升高更明显 ,西比灵能明显降低脑缺血再灌注期间脑水含量。②西比灵降低LPO含量 ,稳定SOD活性。③图像分析显示西比灵可增加再灌注后神经元面数密度。结论　西比灵不但可防止Ca2 过量跨膜进入细胞内 ,还具有抑制血由基生成的作用 ,减轻脑水肿 ,减轻脑组织的病理损害 ,从而在脑缺血再灌注期间达到脑保护作用     

西比灵对大鼠急性脑缺血再灌注损伤自由基影响的实验研究

目的 进一步探讨西比灵对脑缺血再灌注损伤保护作用的机制。方法 采用Ｐｕｌｓｉｎｅｌｉ四血管闭塞法（４ＶＯ）缺备大鼠急性脑缺血再灌注模型,利用Ｔｓｕｃｈｉｄａ的ＷＰＳ法测定ＬＰＯ,利用化学发光法测定ＳＯＤ活性,并观察西比灵对上述指标的影响。结果 西比灵可降低ＬＰＯ含量,稳定ＳＯＤ活性。结论 西比灵可抑制脑缺血再灌注时脑组织内自由基的生成。     

阿托伐他汀联合还原型谷胱甘肽对高脂血症大鼠血脂代谢及抗氧化的影响

目的观察阿托伐他汀（Atorvastatin）联合还原性谷胱甘肽（reduced Glutathione,GSH）对高脂血症大鼠的抗氧化作用及血脂的影响。方法 SD雄性大鼠40只,随机分成5组,每组8只。A组：给予阿托伐他汀。B组：给予还原型谷胱甘肽。C组：给予阿托伐他汀＋还原型谷胱甘肽。D组：高脂血症对照组,给予高脂饲料灌胃。E组：空白对照组,给予普通饲料喂养。结果各药物干预组低密度胆固醇（LDL）,甘油三酯（TG）,血清总胆固醇（TC）,丙氨酸氨基转移酶（ALT）,天门冬氨酸氨基转换酶（AST）,丙二醛（Malondialdehyd,MDA）水平均低于高脂血症组（P〈0.05）,高密度胆固醇（HDL）,超氧化物歧化酶（Superoxide dismutase,SOD）水平均高于高脂血症组（P〈0.05）。C组与A组及B组比较作用更显著（P〈0.05）。结论还原型谷胱甘肽具有抗氧化作用外,还具有调脂作用,可能与阿托伐他汀具有协同作用。