急性心肌梗塞、心绞痛患者红细胞膜结合硒的研究

为了探讨红细胞膜结合硒与急性心肌梗塞、心绞痛的关系,本文对32例急性心肌梗塞、32例心绞痛患者及35例正常人分别进行红细胞膜结合硒测定。结果发现:急性心肌梗塞组红细胞膜结合硒测定值显著低于心绞痛组(分别为7.74±1.29ng/mg膜蛋白和9.32±1.82ng/mg膜蛋白;P<0.01),且两组测定值均、显著低于正常对照组(12.47±3.45ng/mg膜蛋白,P<0.01)。     

硒对加钴引起体外培养心肌细胞损伤的保护作用

目的 观察硒对钴引起心肌细胞损伤的保护作用。方法 分别于体外培养体生Ｗｉｓｔａｒ大鼠心肌细胞培养液中加入钴（４０ｕｇ／ｍｌ）、硒（０．１ｕｇ／ｍｌ）、同时加入钴（４０ｕｇ／ｍｌ）和硒（０．１ｕｇ／ｍｌ）,在培养的不同时期观察心肌细胞形态结构,并测定心肌酶活性。结果 硒能明显减轻钴对心肌细胞形态结构的员伤性改变,并可降低心肌细胞培养液中心肌酶的活性。结论 硒对钴引起心肌细胞损伤有一定的保护作用。     

急性心肌梗塞患者红细胞变形能力与红细胞膜结合硒关系的研究

检测５４例急性心肌梗塞（ＡＭＩ）患者的红细胞变形能力（ＥＤ）与红细胞膜结合硒（Ｅ－Ｓｅ）含量变化，并探讨其间的关系。结果显示，ＡＭＩ病人ＥＤ及Ｅ－Ｓｅ含量均明显降低，且两者之间呈正相关，提示ＡＭＩ病人ＥＤ降低与Ｅ－Ｓｅ含量降低有关。     

铬对低硒状态所致心肌损伤保护机理研究

目的 研究铬对低硒状态所致心肌损伤保护作用，探讨其保护机理。方法 克山病病区粮喂养Wistar大鼠复制低硒动物模型，加铬加硒作为干预因素，观察其生长发育状况；描记心电图；玻璃微电极法测心肌细胞电生理；荧光偏振法测心肌细胞线粒体膜流动性；低温顺磁共振技术测心、肝自由基含量；生化法测血、心、肝GSH-Px及SOD活性；放射免疫法测心肌环磷酸腺苷和甲状腺激素；透射电镜观察心肌超微结构变化。结果 低硒饲料喂养动物生长延迟；心电图及心肌电生理QRS时限、Q-T间期及APD50、APD50延长；心肌细胞膜流动性降低；心肝自由基水平升高、抗氧化酶类GSH-Px及SOD活性降低；甲状腺激素T3、T4及心肌cAMP降低；心肌超微结构显示心肌损伤。铬则可改善低硒动物营养状况，恢复心肌组织生理病理学改变。结论 铬对低硒状态所致心肌损伤具有保护作用，逆转QRS时限、Q-T闻期和APD的改变；提高心肌细胞膜流动性；增强抗氧化酶活性，降低自由基水平及调整甲状腺激素和心肌cAMP代谢则是铬抗低硒心肌损伤的重要作用机制。     

硒和维生素E对大鼠心肌腺苷酸及氧化损伤的影响

目的：研究低硒（Ｓｅ）低维生素Ｅ（ＶＥ）饮食大鼠心肌腺苷酸含量和氧化损伤的关系。方法：使用高效液相测定心肌腺苷酸含量和使用生化方法测定心肌ＭＤＡ含量和ＳＯＤ、ＧＳＨ－Ｐｘ活性。结果：与补充Ｓｅ和／或ＶＥ饮食大鼠相比，低Ｓｅ低ＶＥ饮食大鼠心肌ＡＭＰ，ＡＤＰ含量无明显差异，而ＡＴＰ含量明显降低，ＭＤＡ含量增加，ＳＯＤ，ＧＳＨ－Ｐｘ活性降低，表明Ｓｅ和ＶＥ影响ＡＴＰ含量与其抗氧化作用有关，而其中以联合补充Ｓｅ和ＶＥ效果最佳     

蛋白质氧化羰基化和肌肽的保护作用

目的 探讨肌肤的抗氧化、抗衰老作用的途径和机制。方法用H2O2诱导小鼠新鲜脑组织使其产生氧化碳基化蛋白，用DNPH法和定磷法检测碳基化蛋白的含量和氧化磷酸化水平。结果 在加入肌肤的保护组，碳基化蛋白含量低于损伤组，氧化磷酸化水平高于损伤组，各组差异明显。结论 肌肤对蛋白质氧化碳基化有明显的保护作用。     

脑外伤患者红细胞膜钠钾ATP酶活性变化及其临床意义

动态观察３０例脑外伤患者的红细胞膜钠钾ＡＴＰ酶（下称钠钾ＡＴＰ酶）活性变化。结果显示，钠钾ＡＴＰ酶于伤后１２小时明显下降，２４小时降至最低水平，９６小时开始恢复，１６８小时接近正常。提示脑外伤患者急性期红细胞膜钠钾ＡＴＰ酶活性明显降低，伤情越重，降低越明显。     

不同硒水平对慢性氟中毒大鼠的保护作用

目的：研究不同硒水平对慢性氟中毒大鼠的保护作用。方法：SD大鼠随机分为4个组，3个实验组均饮100mg/L高氟水，其中有2个组饲料加硒，加硒量分别为2．12mg/kg和3．06mg/kg。实验期为4个月，每周测体重，每月收集24h尿，测饮水、摄食及排尿量而后计算其日平均摄氟、排氟量，并每月测尿液氟含量，查氟斑牙发生情况。在实验进行到1个月和4个月时测尿硒含量。实验末处死大鼠后查氟骨症发生情况、取骨组织观察病理形态变化。结果：3个实验组与对照组比较摄氟量升高，排氟与摄氟比值降低，尿氟浓度升高，2个加硒组较未加硒组排氟与摄氟比值升高，早期大鼠尿氟浓度升高明显，氟骨症、氟斑牙发生例数减少，病理资料显示骨组织中骨小梁粗细较均匀，排列有序。与此同时大鼠饮水、摄食状况改善、体重增加，排尿量升高。且饲加硒3mg/kg饲料组上述效果较饲加硒2mg/kg饲料组明显。结论：硒对氟有拮抗作用，每公斤饲料加硒3mg以下时，硒的拮抗作用随硒量增加而增强。     

遗传性红细胞膜病与红细胞膜蛋白的基因改变

遗传性红细胞膜病，包括遗传性球形细胞增多症（HS）、遗传性椭圆形细胞增多症（HE）、遗传性热异形细胞增多症（HPP）、东南亚卵圆形细胞增多症（SAO）和遗传性口形细胞增多症（HSt）等。这些疾病大多具有临床和实验室的异质性。近年来对其分子水平的研究显示在这些疾病中也呈现出明显的遗传学异质性，尤其是在HS中，几乎每个家系都有球形细胞增多症基因自己独特的一个突变。     

Vitamins C and E protect isolated cardiomyocytes against oxidative damage

There is considerable evidence that oxygen free radicals are involved in reperfusion injury of ischemic myocardium. Epidemiologic studies showed an inverse correlation between plasma levels of alpha-tocopherol (vitamin E) and ascorbic acid (vitamin C) and mortality from ischemic heart disease. The present study examines the influence of both vitamins on the toxic effects of singlet oxygen on isolated rat cardiomyocytes. Freshly isolated cardiomyocytes from adult rats were exposed to singlet oxygen which was generated by photoactivation of the photosensitive dye rose bengal (10(-7) M). This procedure induced irreversible hypercontracture in about 95% of rod-shaped cardiomyocytes within 15 min after onset of photoactivation of rose bengal. Pretreatment with vitamin C (10(-5) to 10(-2) M) or E (10(-6) to 10(-3) M) reduced the number of hypercontracted cells after exposure to singlet oxygen in a concentration-dependent manner. Simultaneous application of both vitamins (vitamin E 10(-6) M plus vitamin C 10(-5) M or vitamin E 10(-5) M plus vitamin C 10(-4) M) revealed a marked overadditive protective effect against oxidative damage as compared with the single application of each vitamin. Our data show that alpha-tocopherol and ascorbic acid exert direct protective actions on isolated cardiomyocytes against oxidative damage and provide an overadditive effect if administered simultaneously.     

Fluorocarbon cardioplegia to protect the myocardium from ischemic damage

A comparative assessment of the protective effect of cardioplegic solutions (novocain-containing and based on fluorocarbon emulsions) on isolated canine hearts showed the cardioplegic solutions based on fluorocarbon emulsions to be more conducive to the recovery of electrical and mechanical properties of the myocardium.     

Sacubitril and valsartan protect from experimental myocardial infarction by ameliorating oxidative damage in Wistar rats

Background: Sacubitril (SAC), a neprilysin inhibitor prevent degradation of neprilysin and activate cGMP signaling pathways leading to rise in blood volume concurrent to blood pressure by means of vasoactive peptides, adrenomedullin, and bradykinin.

Objective: The aim of this study was to evaluate the anti-ischemic effects of SAC through inhibiting neprilysin in isoproterenol (ISO) induced myocardial infarction (MI) in Wistar albino rats. ISO (85 mg/kg) was injected subcutaneously at the end of 14 days pre-treatment with SAC and valsartan (VAL).

Result: Biochemical investigation revealed that SAC along with VAL significantly prevented the antioxidant enzymes (SOD, Catalase, GR, GPx, GST, and GSH) degradation and malondialdehyde (MDA) induced by ISO intoxication in Wistar rats. Along with this, cardiac biomarkers (LDH, CK-MB, ALT, AST, and ALP) were also significantly ameliorated by SACand VAL in ISO-treated rats. Concurrently, decreased infarction area (IA)and marked reduction in myofibril damage by SACand VAL further supported its protective benefits in MI.

Conclusion: Taken together, the results suggest that inhibition of enzyme neprilysin alleviated the ISO induces myocardial damage mediated by its strong antioxidant potential.     

Reduced susceptibility to peroxidation of erythrocyte plasma membranes from centenarians

The plasma membrane composition affects intracellular processes and the cellular susceptibility to free radical attack, which has been associated with the impairment of cellular functions occurring during senescence. The study of the modifications of the plasma membrane in centenarians might elucidate the biological mechanisms at the basis of longevity and successful aging. The work was performed in 190 subjects, divided into five groups according to the age range: (1) 21-40 years (n=25); (2) 41-60 years (n=30); (3) 61-80 years (n=30); (4) 81-99 years (n=50); and (5) centenarians (> or = 100 years) (n=55). The following determinations were performed on erythrocyte membranes: (i) the lipid peroxide level (Lp) evaluated as malondialdehyde content; (ii) susceptibility to in vitro oxidation evaluated as difference in the content of thiobarbituric acid-reactive substances before and after phenylhydrazine addition; (iii) unsaturated/saturated fatty acid ratio and individual polyunsaturated fatty acid composition measured by gas chromatography; and (iv) fluidity studied by means of the anisotropy of the probe 1-(4-trimethylaminophenyl)-6-phenyl-1,3,5-hexatriene (TMA-DPH). Erythrocyte membranes from centenarians showed: (i) decreased basal lipid peroxide levels and reduced susceptibility to peroxidation in comparison with elderly subjects; (ii) increased unsaturated/saturated fatty acid ratio in comparison with every other age group; (iii) higher levels of eicosapentaenoic and docosahexaenoic acid and reduced content of linoleic and arachidonic acid in comparison with elderly subjects; and (iv) decreased anisotropy of TMA-DPH, i.e. higher fluidity compared with all the other age groups. In conclusion, the present work demonstrates that erythrocyte membranes from centenarians show some distinct features in comparison with elderly subjects that might act in a protective way against injuries.     

羟自由基对红细胞膜的损伤作用研究

应用Ｆｅｎｔｏｎ反应系统介导产生的人红细胞体外损伤模型，观察红细胞低渗溶血速率及红细胞ＮＯ_２~－阴离子通透性的改变。结果显示：低渗溶血通率，ｋ_１值在以低剂量Ｈ_２Ｏ_２（１００ｍｍｏｌ／Ｌ）处理时；与对照组相比有增加，在以高剂量Ｈ_２Ｏ_２（２００ｍｍｏｌ／Ｌ）处理时则降低，呈双向性反应；ｋ_２值各组间经统计学处理均无显著差异。红细胞ＮＯ_２~－阴离子通透性：反映膜ｂａｕｄ３蛋白的阴离子运输状况，在Ｈ_２Ｏ_２１００ｍｍｏｌ／Ｌ和２００ｍｍｏｌ／Ｌ两种剂量作用下，通透性均增加。根据以上观察结果，再结合氧化红细胞的形态学改变结果来进行分析，将有助于理解红细胞衰老过程中细胞膜囊泡化脱落，以及衰老抗原的形成。     

Increased susceptibility to oxidative damage in post-diabetic human myotubes

Aims/hypothesis  

Obesity is an important risk factor for the development of type 2 diabetes, but not all obese individuals develop this complication. The clinical signs of type 2 diabetes can often be reversed with weight loss; however, it is unknown whether the skeletal muscle oxidative stress associated with type 2 diabetes remains after weight loss. We hypothesised that chronic exposure to high glucose and insulin would re-elicit impaired metabolism in primary myotubes from patients with a history of type 2 diabetes.     

Myosin in adult and neonatal human erythrocyte membranes

The heavy chain of myosin can be detected in human red cell membranes by immunoblot analysis with antiplatelet myosin antibodies. Neonatal red cell membranes have more immunoreactive myosin than adult membranes. Membranes from young adult red cells contain more immunoreactive myosin than membranes from old adult red cells. In contrast, young and old neonatal red cells have equivalent mounts of myosin. Erythrocyte myosin is present in a membrane fraction enriched in integral membrane proteins but is not found in cytoskeletal preparations.     

The importance of selenium to human health

The essential trace mineral, selenium, is of fundamental importance to human health. As a constituent of selenoproteins, selenium has structural and enzymic roles, in the latter context being best-known as an antioxidant and catalyst for the production of active thyroid hormone. Selenium is needed for the proper functioning of the immune system, and appears to be a key nutrient in counteracting the development of virulence and inhibiting HIV progression to AIDS. It is required for sperm motility and may reduce the risk of miscarriage. Deficiency has been linked to adverse mood states. Findings have been equivocal in linking selenium to cardiovascular disease risk although other conditions involving oxidative stress and inflammation have shown benefits of a higher selenium status. An elevated selenium intake may be associated with reduced cancer risk. Large clinical trials are now planned to confirm or refute this hypothesis. In the context of these health effects, low or diminishing selenium status in some parts of the world, notably in some European countries, is giving cause for concern.