替米沙坦对大鼠急性心肌梗死后心肌成纤维细胞的影响

目的观察替米沙坦对大鼠急性心肌梗死(AMI)后梗死区和非梗死区的心肌成纤维细胞活化、增殖和心肌纤维化的动态影响。方法结扎大鼠左冠状动脉前降支造成 AMI.术后24 h存活114只.随机分为 AMI 组和替米沙坦治疗组(治疗组),另设假手术组。治疗组于每天上午8时灌胃(替米沙坦60 mg·kg~(-1)·d~(-1)),其余均喂食等量蒸馏水,于4、7、14 d和28 d后测量大鼠心率、血压、心室重量/体重(VW/BW),并计算存活率及梗死区和非梗死区心肌成纤维细胞活化、增殖和胶原容积分数(CVF)。结果 (1)28 d时,治疗组的累积存活率明显高于 AMI 组(45%和40%,P<0.05);14、28 d时治疗组心室相对重量明显低于 AMI 组(P<0.05)。(2)梗死后4 d,AMI 组和治疗组大鼠的梗死区出现大量的α-平滑肌肌动蛋白(α-SMA)和波形蛋白 VA 表型阳性细胞,7 d后逐步降低;同时该区细胞增殖细胞核抗原(PCNA)染色阳性;28 d时,治疗组α-SMA 及 PCNA 阳性率明显低于 AMI 组(P<0.05),而在非梗死区,α-SMA 及 PCNA 阳性率较低,各组间差异无统计学意义。(3)28 d时,治疗组梗死区 CVF 明显低于 AMI 组(P<0.05);在非梗死区,14、28 d时,治疗组 CVF 明显低于 AMI 组(P<0.01)。结论替米沙坦可改善大鼠 AMI 后心室重构并降低病死率,可明显抑制梗死区成纤维细胞表型转化和增殖,并降低梗死区和非梗死区 CVF。     

血管紧张素Ⅱ对高血压大鼠心肌成纤维细胞作用研究

目的 研究血管紧张素Ⅱ(AngⅡ)对自发性高血压大鼠左心室心肌成纤维细胞促生长作用以及可能存在的信号传导途径。方法 体外培养心肌成纤维细胞(CFB)，分别加入不同浓度AngⅡ、AT1R拮抗剂洛沙坦、酪氨酸蛋白激酶抑制剂(Genistein)，测定细胞^3H—TdR和^3H—Leu掺入率。结果 AngⅡ浓度依赖性促进CFB的^3H—TdR和^3H—Leu掺入率，洛沙坦可完全抑制该效应．Genistein部分抑制该效应。结论 外源性AngⅡ通过CFB的AT1R对该细胞产生增殖反应，作用的信号传导途径部分是由酪氨酸蛋白激酶系统介导。     

AngⅡ、TGF-β1和FN对自发性高血压大鼠心肌成纤维细胞合成胶原的影响

目的　观察血管紧张素Ⅱ（AngⅡ）、转化生长因子β1（TGF-β1）、洛沙坦（Losartan）、纤维粘连蛋白（FN）对培养的SHR和WKY大鼠心肌成纤维细胞（CFb）合成胶原的影响。方法　采用组织块贴壁法培养CFb,分别测定AngⅡ、TGF-β1、Losartan、FN干预下CFb的　3H-脯氨酸（　3H-Proline）掺入量。结果　AngⅡ、TGF-β1、FN促进CFb的　3H-Proline掺入量,Losartan抑制10-7MAngⅡ诱导的CFb的　3H-Proline掺入。结论　AngⅡ、TGF-β1、FN对CFb的胶原合成有促进作用,Losartan可拮抗AngⅡ的作用。     

血管紧张素Ⅱ对高血压大鼠心肌成纤维细胞作用研究

目的研究血管紧张素Ⅱ(AngⅡ)对自发性高血压大鼠左心室心肌成纤维细胞促生长作用以及可能存在的信号传导途径.方法体外培养心肌成纤维细胞(CFB),分别加入不同浓度Ang Ⅱ、AT1R拮抗剂洛沙坦、酪氨酸蛋白激酶抑制剂(Genistein),测定细胞3H-TdR和3H-Leu掺入率.结果 Ang Ⅱ浓度依赖性促进CFB的3H-TdR和3H-Leu掺入率,洛沙坦可完全抑制该效应,Genistein部分抑制该效应.结论外源性AngⅡ通过CFB的AT1R 对该细胞产生增殖反应,作用的信号传导途径部分是由酪氨酸蛋白激酶系统介导.     

心肌成纤维细胞在血管紧张素Ⅱ致心脏间质纤维化中的作用

在心脏纤维化过程中，心肌成纤维细胞扮演着重要角色。血管紧张素Ⅱ可增加心肌成纤维细胞合成，分泌整合素、骨桥素等粘附分子，从而诱导细胞外基质蛋白合成，促进间质纤维化。     

辛伐他汀对脂多糖诱导新生大鼠心肌成纤维细胞NO生成和AT2R蛋白表达抑制的影响

目的研究辛伐他汀（Sim）对脂多糖（LPS）调控心肌成纤维细胞（CFs）一氧化氮（NO）生成和血管紧张素Ⅱ受体2型（AT2R）蛋白表达的干预效应。方法体外培养新生大鼠CFs,以第1代CFs作为实验对象,采用硝酸还原酶法测定细胞内NO产量,Western blot检测细胞AT2R蛋白的表达,以AT2R/β-actin值对AT2R表达进行半定量。结果与LPS（10mg/L）单独作用组相比,0.01μmol/L和0.1μmol/L Sim与LPS共同作用组CFs的NO生成和AT2R/β-actin值无显著差异;在1μmol/L和10μmol/LSim与LPS共同作用组,NO生成量显著低于LPS单独作用组（均P<0.01）,而AT2R/β-actin值显著高于LPS单独作用组（分别有P<0.05和P<0.01）。结论高浓度Sim可拮抗LPS引起的NO生成增加和AT2R蛋白表达下降。     

血管紧张素Ⅱ对人肾成纤维细胞的影响

目的：观察血管紧张素Ⅱ（ＡｎｇⅡ）对人肾成纤维细胞（ＫＦＢ）的影响。方法：采用ＥＬＩＳＡ法,四甲基偶氮唑蓝（ＭＴＴ）法、流式细胞仪、免疫组织化学法分别检测ＡｎｇⅡ对ＫＦＢ分泌的胶原酶活性、ＫＦＢ增生、凋亡、Ⅰ型胶原表达的影响。结果;ＡｎｇⅡ能提高ＫＦＢ分泌的总胶原活性、促进味道一、抑制ＫＦＢ凋亡、促进ＫＦＢⅠ型胶原的表达。结论：ＡｎｇⅡ能通过促进ＫＦＢ增生、抑制ＫＦＢ凋亡、促进ＫＦＢⅠ型胶原的表达     

Benazepril和Losartan对培养SHR心肌成纤维细胞增殖及合成胶原影响

目的　观察血管紧张素Ⅱ (AngⅡ )、苯那普利 (Benazepril,Be na)、洛沙坦 (Losartan)对培养的SHR和WKY大鼠心肌成纤维细胞 (CFb)增殖及合成胶原的影响。方法　采用组织块贴壁法培养CFb ,分别测定AngⅡ、Bena干预下CFb的增殖情况 ,AngⅡ、Bena和Losartan干预下CFb的3H 脯氨酸 (3H Proline)掺入量。结果　各种浓度的AngⅡ (10 -10 mol～ 10 -6mol)和Bena(10 -9mol～ 10 -5mol)对CFb的细胞数显著增殖无影响 ,AngⅡ呈浓度依赖性促进CFb的3H Proline掺入量 ,Bena抑制CFb的3H Proline掺入量 ,Losartan呈浓度依赖性抑制 10 -7molAngⅡ诱导的CFb的胶原合成。结论　AngⅡ和Bena不影响CFb的增殖 ,AngⅡ对CFb的胶原合成有促进作用 ,Bena抑制CFb胶原合成 ,Losartan可拮抗AngⅡ的作用     

血管紧张素Ⅱ及氯沙坦对糖尿病大鼠心肌成纤维细胞α1(Ⅰ)前胶原mRNA和蛋白表达的影响

目的 探讨血管紧张素Ⅱ(ATⅡ)及其1型受体阻断剂氯沙坦对糖尿病动物模型心肌成纤维细胞α1(Ⅰ)前胶原mRNA和蛋白表达的作用。方法 用链脲佐菌素制备糖尿病大鼠模型，饲养12周后分离心肌成纤维细胞进行原代培养。分别将一定浓度的ATⅡ(10^-9～10^-7mmol／L)，和ATⅡ10^-7 mmol／L加上不同浓度ATⅡ受体阻滞剂氯沙坦(10^-7～10^-5mmol／L)加入细胞培养液中刺激48h，分别采用逆转录聚合酶链反应(RT-PCR)及Western印迹方法检测大鼠心肌成纤维细胞α1(I)前胶原的mRNA及蛋白表达。结果体外成功地培养糖尿病心肌成纤维细胞，并经免疫组化染色结果证实。经ATⅡ刺激48h后，α1(Ⅰ)前胶原mRNA和蛋白表达量明显增高，增高程度与ATⅡ浓度呈正比；加入氯沙坦后，前胶原mRNA和蛋白表达量较单用ATⅡ组下降，也呈浓度依赖性。结论 ATⅡ可促进糖尿病大鼠心肌成纤维细胞的胶原合成，可能在糖尿病大鼠心肌纤维化倾向中起重要作用，该作用可能主要通过ATⅡ1型受体介导完成。     

Benazepril和Losartan对培养SHR心肌成纤维细胞增殖及合成胶原影响

目的观察血管紧张素Ⅱ（AngⅡ）、苯那普利（Benazepril,Bena）、洛沙坦（Losartan）对培养的SHR和WKY大鼠心肌成纤维细胞（CFb）增殖及合成胶原的影响。 方法　采用组织块贴壁法培养CFb,分别测定AngⅡ、Bena干预下CFb的增殖情况,AngⅡ、Bena和Losartan干预下CFb的     

Oxidative Stress and the Myelodysplastic Syndromes

The evolution of higher organisms from anaerobic to aerobic living has promoted an elaborate mechanism of defense against potentially toxic oxidants. Many environmental toxicants implicated in the pathogenesis of myelodysplastic syndromes (MDS), including benzene and ionizing radiation, exert toxicity via pro-oxidant mechanisms. The emerging data suggest a probable genetic susceptibility to environmental carcinogenesis through functional polymorphic variants in enzymes that metabolize toxicants and/or protect against oxidative stress. The most studied enzyme is NAD(P)H:quinone oxidoreductase (NQO1). CD34+ cells from individuals homozygous for the NQO1 C609T nonfunctional allelic variant are incapable of enzyme induction following exposure to benzene, thus potentially increasing the hematotoxicity of benzene metabolites. Serologic and molecular markers of oxidative stress are present in many patients with MDS and include an increased concentration of the lipid peroxidation product malondialdehyde and the presence of oxidized bases in CD34+ cells. Potential mechanisms of oxidative stress include mitochondrial dysfunction via iron overload and mitochondrial DNA mutation, systemic inflammation, and bone marrow stromal defects. The biological activity of the antioxidant aminothiol amifostine in vivo suggests that these pathways may be meaningful targets for future therapy in MDS patients.     

The DOCA-Salt Hypertensive Rat as a Model of Cardiovascular Oxidative and Inflammatory Stress

Oxidative stress and inflammation are two sides of the same coin that are intricately combined to elicit a chronic pathophysiological stress state, especially as seen in cardiovascular remodelling. In this review, we argue that administration of deoxycorticosterone acetate (DOCA) and sodium chloride to uninephrectomised rats, defined as DOCA-salt hypertensive rats, provides a reliable animal model of oxidative and inflammatory stress in the cardiovascular system. The supporting evidence includes pathophysiological and biochemical changes together with pharmacological responses to synthetic and natural compounds that lower the concentrations of reactive free radical species and that curtail inflammatory responses in the cardiovascular system.     

Oxidative Stress in the Dahl Salt-Sensitive Hypertensive Rat

Oxidative stress has been proposed as important in the pathogenesis of hypertension. Measurement of 8-iso prostaglandin F_2α(8-ISO) is introduced for evaluating oxidative stress in vivo. 8-ISO is the major urinary metabolite of F₂-isoprostanes and is formed nonenzymatically from the attack of superoxide radicals on arachidonic acid. We examined the oxidative stress level in the Dahl salt-sensitive (Dahl-S) rats and the Dahl salt-resistant (Dahl-R) rats. Dahl-S and Dahl-R rats were fed either a high salt diet (8% NaCl; HS) or low salt diet (0.3% NaCl; LS) for 3 weeks, and systolic blood pressure (SBP) and 24-hr urinary excretion of 8-ISO (U-8-ISO) were measured. In Dahl-S rats, the high salt diet induced hypertension (139 ± 3 mmHg in LS versus 186 ± 2 mmHg in HS, p < .05) and significantly increased the U-8-ISO (24.9 ± 3.6 ng/24 hr in LS versus 63.2 ± 14.6 ng/24 hr in HS, p < .05). No significant difference in blood pressure or U-8-ISO was observed between high-salt and low-salt treated Dahl-R rats. U-8-ISO concentration was correlated with SBP in all four experimental groups (r = 0.866). Moreover, urinary 8-hydroxy-2′-deoxyguanosine (U-8-OHdG), which is one of the most commonly used markers for evaluation of oxidative stress, was higher in Dahl-S-8% rats than in Dahl-S-0.3% rats (136.1 ± 48.4 ng/24 hr in LS versus 322.8 ± 46.7 ng/24 hr in HS, p < .05), and U-8-OHdG was correlated with SBP (r = 0.681) in Dahl-S rats. These results suggest oxygen radicals are involved in the pathogenesis of hypertension.     

In Utero Ethanol Exposure Elicits Oxidative Stress in the Rat Fetus

Prior studies in our laboratory have shown that exposure of cultured fetal rat hepatocytes to ethanol (E) blocks epidermal growth factor-dependent replication and that this is paralleled by cell membrane damage, mitochondrial dysfunction, membrane lipid peroxidation (LP), and enhanced generation of reactive oxygen species. These measures of E-mediated oxidative stress (OS) were mitigated by treatment with antioxidants, and cell replication could be normalized by maintaining cell glutathione (GSH) pools. We have now extended these studies to an in vivo model. Rats were administered E (4 g/kg, po) at 12-hr intervals on days 17 and 18 of gestation and killed on day 19,1 hr following a final dose of E (a total of 5 doses). Fetal and maternal brain and liver were assayed for signs of OS. The 2-day in utero E exposure increased membrane LP in fetal brain as evidenced by increased malondialdehyde (MDA) levels from 1.76 ± 0.12 se (nMol/mg protein) to 2.00 ± 0.08 (p < 0.05) and conjugated dienes from 0.230 ± 0.006 se (OD₂₃₃/mg lipid) to 0.282 ± 0.006 (p < 0.05). In fetal liver, MDA levels increased from 2.39 ± 0.08 se (nMol/mg protein) to 2.87 ± 0.08 (p < 0.05), whereas dienes differed significantly only between ad libitum controls and the E and pair-fed control groups (p < 0.05). E decreased GSH levels in fetal brain by 19%, from 19.88 ± 0.72 to 16.13 ± 1.06 (nMol/mg protein) (p < 0.05). A10% decrease in GSH was seen in fetal liver (p < 0.05). GSH in maternal brain was decreased by 44% from 47.29 ± 3.38 to 26.60 ± 2.29 (p < 0.05). Other E-related increases in these OS measures were not observed in maternal organs. E did not decrease α-tocopherol levels in fetal and maternal brain or in fetal liver (p < 0.05), whereas maternal liver α-tocopherol content was reduced by 31% (p < 0.05) by E treatment. It is concluded that maternal E consumption can induce an OS in fetal tissues that may contribute to the fetotoxic effects of E.     

自噬与2型糖尿病

自噬是机体处于物质与能量代谢障碍时主要防御机制之一,在维持胰岛β细胞结构功能、改善IR等方面有重要作用。某些治疗T2DM药物也参与自噬途径调节。本文就近年关于自噬对T2DM影响的相关研究进行综述。     

急性柯萨奇病毒性心肌炎与氧化应激

目的　探讨急性柯萨奇病毒性心肌炎 (ACM)患者体内的氧化应激。方法　采用分光光度分析法检测 50例ACM患者和 50例健康志愿者 (对照组 )的血浆谷胱甘肽_S_转移酶 (GST)和过氧化脂质 (LPO)值及红细胞谷胱甘肽过氧化物酶 (GPX)和过氧化脂质 (LPO)值。结果　与对照组比较 ,ACM患者组的血浆LPO和红细胞LPO平均值显著升高 (P <0 0 1～ 0 0 0 1) ,而血浆GST和红细胞GPX平均值显著降低 (P <0 0 0 1) ;ACM患者随着GST值的降低 ,血浆LPO和红细胞LPO值逐渐升高 (P <0 0 1～ 0 0 0 1) ,而红细胞GPX值逐渐降低 (P <0 0 0 1) ;ACM患者遭受潜在氧化损伤的危险度至少是对照组的 2 2倍 ,而最大可达 139 8倍。结论　ACM患者体内一系列自由基连锁反应加剧 ,从而引起了严重的氧化应激和潜在的氧化损伤     

Dexrazoxane Prevents Myocardial Ischemia/Reperfusion-Induced Oxidative Stress in the Rat Heart

Introduction Dexrazoxane (Dex), used clinically to protect against anthracycline-induced cardiotoxicity, possesses iron-chelating properties. The present study was designed to examine whether Dex could inhibit the ischemia/reperfusion (I/R) induced damage to the rat heart. Materials and methods Isolated perfused rat hearts were exposed to global ischemia (37°C) and 60 min reperfusion. Dex was perfused for 10 min prior to the ischemia, or administered intraperitoneally (150 mg) 30 min prior to anesthesia of the rats. I/R caused a significant hemodynamic function decline in control hearts during the reperfusion (e.g., the work index LVDP X HR declined to 42.7 ± 10%). Dex (200 μM) applied during the preischemia significantly increased the hemodynamic recovery following reperfusion (LVDP X HR recovered to 55.7 ± 8.8%, p < 0.05 vs. control). Intraperitoneal Dex, too, significantly increased the hemodynamic recovery of the reperfused hearts. I/R caused an increase in oxidation of cytosolic proteins, while Dex decreased this oxidation. Discussion The decrease in proteins carbonylation and correlative hemodynamic improvement suggests that Dex decreases I/R free radical formation and reperfusion injury. Eyal Ramu and Amit Korach contributed equally to this study.     

Enhanced Oxidative Stress and Leucocyte Activation in Neoplastic Tissues of the Colon

Excess of intracellular reactive oxygen species results in an environment that may modulate gene expression, or damage cellular molecules. These events are assumed to contribute to the process of carcinogenesis. In the present study, we measured the extent of lipid peroxidation and antioxidative status in colonic tumors and normal colonic mucosa obtained from 25 patients with colorectal carcinoma. Levels of lipid peroxides (PD) and of thiobarbituric acid reactive substances (TBARS) were significantly increased, by 54 and 59%, respectively, in tissue specimens obtained from the colonic tumor as compared with normal colonic mucosa (PD, 2.78±0.31 versus 1.81±0.29 nmol/mg tissue, TBARS, 0.86±0.1 versus 0.54±0.08 nmol/mg tissue). Activities of the antioxidant enzymes catalase and glutathione peroxidase (GPx) were also higher (by 67 and 29%, respectively) than in normal mucosa, probably in response to the increased free radical stress occurring in cancerous tissues. Myeloperoxidase (MPO) and adenosine deaminase (ADA) are markers of activated leukocytes and are related to the production of oxygen free radicals by these cells. Their activities were significantly elevated in the neoplastic tissue as compared to the normal tissue (MPO, 7.4±1.5 versus 4.1±0.95 U/mg tissue, ADA, 4.17±0.65 versus 2.99±0.80 U/g tissue), suggesting a possible involvement of activated leukocytes in the enhanced oxidative stress in the cancerous tissue. Our results demonstrate an enhanced oxidative stress in the neoplastic tissue. Leukocyte activation was also higher in the carcinogenic tissue, indicating a possible contribution of these cells to a further oxidative stress-derived tissue injury. These observations add to previous studies and may encourage therapeutic trials with antioxidants as a means of preventing colorectal cancer and preventing further tissue injury in the neoplastic tissue and its surroundings.