异丙酚对大鼠胃缺血再灌注损伤的影响

目的观察异丙酚对大鼠胃缺血再灌注损伤（gastricischemia—reperfusion injury，GI—RI）的影响。方法30只SD大鼠，随机分为3组，假手术组（S组）、单纯缺血-再灌注组（I—R组）、异丙酚组（P组）。以夹闭大鼠腹腔动脉30min、松开动脉夹恢复血流灌注1h制备GI—RI模型。计算胃黏膜损伤指数，检测胃黏膜超氧化物歧化酶（supemxide dismutase，SOD）活性和丙二醛（malondialdehyde，MDA）含量。结果静脉注入异丙酚后，胃缺血再灌注导致的胃黏膜损伤减轻，胃黏膜损伤指数明显减少，异丙酚组（P组）与缺血一再灌注组（I—R组）比较，胃黏膜中MDA含量下降，SOD活性升高。结论异丙酚对GI—RI具有明显的保护作用。这种保护作用可能是通过异丙酚的抗氧化作用实现的。     

自然流产妇女血清MDA、SOD、VitE的测定及意义

目的:通过对自然流产妇女血清氧化应激指标———超氧化物歧化酶(SOD)、丙二醛(MDA)及维生素E(V itE)的测定,分析三个指标在自然流产发病机制中的意义。方法:用化学比色法对30例自然流产妇女及20例正常早孕组妇女血清中SOD、MDA及V it E进行测定。结果:与正常早孕妇女相比,自然流产妇女血清中MDA水平升高(P<0.05),SOD、V it E水平却下降(均P<0.05)。结论:上述三个指标对于预防及治疗自然流产有重要意义。     

硫氧还蛋白对大鼠睾丸缺血再灌注损伤保护作用的研究

目的 探讨硫氧还蛋白对大鼠睾丸缺血再灌注损伤的保护作用.方法 选取雄性SD大鼠60只,随机分为4组:假手术对照组(A组);睾丸扭转/复位组(B组);睾丸扭转/复位+腹腔内注射生理盐水组(C组);睾丸扭转/复位+腹腔内注射硫氧还蛋白组(D组).无菌条件下制作左侧睾丸扭转模型,扭转持续4h,复位4h后取睾丸标本(D组在复位前15 min腹腔内注射硫氧还蛋白).对标本进行病理组织学检查;检测睾丸组织中超氧化物歧化酶(SOD)和丙二醛(MDA)的含量.结果 睾丸扭转/复位后可见生精小管退变,间质出现水肿及出血,腹腔注射硫氧还蛋白使睾丸扭转/复位诱发的组织学改变明显改善.B组及C组睾丸损伤评分(8.3±0.96;8±0.87)明显高于A组(0.78±0.36)(P＜0.01),而腹腔注射硫氧还蛋白可以使睾丸损伤分值(3.1±0.42)显著降低(P＜0.05).B组及C组MDA含量(4.39±0.21;4.42±0.17)升高,SOD活性(269±27.1;271±21.3)降低,与对照组(MDA:1.61±0.18;SOD:317±22.3)相比,差别具有显著性意义(P＜0.01).而腹腔注射硫氧还蛋白能有效降低MDA含量(2.03±0.03)并升高SOD活性(315±24.2)(P＜0.01).结论 本实验为硫氧还蛋白作为治疗睾丸扭转继发损害的有效物质提供了组织学及生化依据.为临床预防和治疗睾丸缺血再灌注损伤提供了理论依据.     

Prognostic implications of ischemia modified albumin in known cases of 86 elderly hypertensive South Asian aged 56–64 years – a hospital based study

ObjectiveTo study associated ischemia modified albumin in hypertensive participants and to compare the results with normotensive healthy controls.MethodsA total of 86 hypertensive patients and 86 age-sex matched normotensive healthy volunteers were selected for this study. The study was conducted for a period of 3 years from September 2007 to August 2010. Biochemical parameters and other parameters such as smoking habits, systolic and diastolic blood pressure and family history were recorded. Lipid profile, ischemia modified albumin, malondialdehyde and conjugated diene were measured by standard methods and results were compared between patients and controls.ResultsTotal cholesterol, triglycerides, low density lipoprotein cholesterol were significantly higher (P<0.001) in hypertensive subjects when compared to normotensive control. Also, significant differences were seen in high density lipoprotein cholesterol levels between both groups (P<0.001). The index of lipid per oxidation comprising both malondialdehyde and conjugated dienes were significantly higher in hypertensive compared to normotensive controls. Ischemia modified albumin levels were significantly increased among hypertensive compared to normotensive controls (P<0.001).ConclusionsHypertensive patients have increased oxidative stress and are accompanied with rise in ischemia modified albumin. Ischemia modified albumin could be incorporated as a diagnostic test parameter in hypertensive to avoid the future acute coronary complications.     

Renal injury induced in alloxan diabetic rats. Role of Mycophenolate Mofetil as therapeutic agent

BackgroundRenal injury may develop in uncontrolled chronic hyperglycemia due to increased oxidative stress and release of pro-inflammatory mediators, leading to diabetic complications.MethodsMycophenolate Mofetil (MMF) is an immunosuppressant drug, an inhibitor of inosine monophosphate dehydrogenase (IMPDH), relevant to inflammation processes. MMF effect was tested in alloxan-diabetic rats on selected parameters like oxidative stress, gene expression of tumor necrosis factor-α (TNF-α) and transforming growth factor-β1 (TGF-β1), in relation to microalbuminuria and renal function.ResultsWe found that the onset of microalbuminuria preceded the increase in serum glucose after alloxan treatment. Gene expression of TNF-α and TGF-β1 showed gradual increase after one and two weeks of alloxan administration as compared to the normal group. MMF administration decreased the gene expression of TNF-α and TGF-β1 in kidney tissues, serum glucose, fructosamine, urea, creatinine, C-reactive protein, malondialdehyde, urinary microalbumin and total protein. Histological examination of kidney tissues showed significant improvement in MMF treated rats as compared to diabetic control.ConclusionsMMF modulated renal injury of alloxan diabetic rats. Collective data may support its therapeutic effect but further clinical trials may be requested.     

The Ginkgo biloba extract (GbE) protects the kidney from damage produced by a single and low dose of carbon tetrachloride in adult male rats

Gingko biloba leaves have been used as herbal medicine in China for 5000 years, and the standardized leaf extract (GB-STE) has some beneficial effects in the treatment of age-related, cardiovascular, and neurological diseases. The aim of this study was to investigate the renoprotective effects of the Gingko biloba extract (GbE) against the toxicity of a single and relatively low dose of carbon tetrachloride (CCl₄). In male adult Wistar rats, we determined the urine flux, the concentration of total proteins in urine, the concentration of glucose in urine, and the concentration of malondialdehyde (MDA) in renal cortex as well as two markers of renal function (clearance of inulin and p-aminohippurate); we also compared the histological lesions caused by CCl₄. Carbon tetrachloride increased the urinary concentration of total proteins, and the renal concentration of MDA; however, it did not modify the urine flux, urinary concentration of glucose, nor the inuline or the p-aminohipurate clearances. Morphologically, CCl₄ generated some tubular damage that was more intense in the inner cortex of kidneys. The GbE extract counteracted the effects of CCl₄ on the concentration of total proteins in urine, the concentration of renal MDA, and the renal histological changes. In conclusion the main toxic effects produced by CCl₄ were prevented by the GbE, probably due to their antioxidant properties and the inhibition of the main P450 isoenzyme (CYP2E1) that metabolize CCl₄.     

17β雌二醇对大鼠创伤性脑损伤的保护作用

目的 探讨大鼠创伤性脑损伤后17β雌二醇对脑组织的保护作用。方法 选择雄性成年 SD大鼠 45 只, 按随机数字表法分为三组, 每组15只: 对照组仅开骨窗, 不损伤脑组织;致伤组制大鼠自由落体脑撞击伤模型;处理组在致伤组的基础上, 伤前1周腹腔注射17β雌二醇溶液(1 mg/kg), 1次/d。余两组仅注射同体积的蓖麻油。在伤后 6 h、 24 h 及48 h 测量各组脑组织含水量、 丙二醛(MDA)含量及超氧化物歧化酶(SOD)活性。结果 致伤组和处理组在伤后 6 h、24 h、48 h 三个时间点脑组织含水量均高于对照组(P<0.05)。在伤后 6 h, 致伤组和处理组脑组织含水量比较差异无统计学意义[(58.39±0.29)%比(57.03±0.27)%] (P> 0.05), 而在伤后24 h、48 h 致伤组脑组织含水量明显高于处理组,差异有统计学意义 [(67.41±0.37)%比(64.77±0.33)%, (81.95±0.47)%比(75.26±0.41)%](P<0.05)。在伤后 6 h 致伤组、处理组 MDA含量明显增加, 并且一直维持在较高水平, 而 SOD活性则明显下降, 与对照组比较差异有统计学意义 (P<0.05)。处理组在伤后6 h MDA含量和 SOD活性与致伤组比较差异无统计学意义(P>0.05), 而在伤后24 h、48 h MDA 含量显著降低[(130.39±7.02) μmol/g 比(149.41±8.25) μmol/g, (125.41±6.59) μmol/g 比(157.72±8.93) μmol/g], SOD活性则明显增高[(88.46±7.17)U/g比(80.10±4.87)U/g, (97.31±7.89)U/g 比(84.29±6.13) U/g], 差异均有统计学意义 (P<0.05)。结论 17β雌二醇对创伤性脑损伤有保护作用。     

断乳至性成熟期暴露纳米二氧化硅对小鼠卵巢发育的影响

目的探讨断乳至性成熟期经口持续摄入纳米二氧化硅对小鼠卵巢发育的影响。方法将40只21日龄清洁级ICR雌性小鼠随机分为4组,即对照组和0.25、0.50、1.00 g/kg纳米二氧化硅染毒组,每组10只。采用经口灌胃方式进行染毒,每日1次,持续染毒5周。实验结束后记录小鼠体重增长情况、观察阴门开放时间和动情周期,病理切片计数各级卵泡数量及计算各级卵泡的构成比,并测定卵巢中丙二醛(MDA)含量和超氧化歧化酶(SOD)、谷胱苷肽过氧化物酶(GSH-Px)活力。结果与对照组比较,1.00 g/kg纳米二氧化硅染毒组小鼠卵巢重量和脏器系数下降、阴门开放时间推迟、卵巢黄体构成比下降、闭锁卵泡构成比升高,差异有统计学意义(P0.05);而各剂量纳米二氧化硅染毒组小鼠体重增长和动情周期均无明显改变。与对照组比较,1.00 g/kg纳米二氧化硅染毒组小鼠卵巢组织中MDA含量明显上升,SOD活力均明显下降,而0.50、1.00 g/kg纳米二氧化硅染毒组小鼠卵巢组织中GSH-Px活力均升高,差异具有统计学意义(P0.05)。结论经口摄入纳米二氧化硅可影响小鼠卵巢发育,其机制可能与氧化损伤有关。     

Lowering of oxidative stress in hemodialysis patients by dialysate cleaning: in relation to arteriosclerosis

The objective of this study was to investigate changes in oxidative stress associated with the cleaning of the dialysate. Thirty-six dialysis patients were studied. Changes in soluble CD-14 (sCD-14), malondialdehyde-low-density lipoprotein (MDA-LDL), and oxidized-LDL (Ox-LDL) were monitored for 1 year before and 1 year after dialysate cleaning. The mean endotoxin (ET) level in the dialysate had previously been confirmed to decrease from 39.0 EU/L to an undetectable level after the cleaning. The mean levels of sCD-14, MDA-LDL, and Ox-LDL decreased significantly after the cleaning (sCD-14, P < 0.0001; MDA-LDL, P < 0.001; Ox-LDL, P < 0.001). One year after the cleaning, six cases still showed high levels of MDA-LDL and Ox-LDL. Cardiovascular events occurred in four of those six cases within 2.8 years after the cleaning. These four patients suffered from strong oxidative stress during dialysis, even after the cleaning. We therefore concluded that high levels of MDA-LDL and Ox-LDL are improved in dialysis patients by cleaning of the dialysate. These results indicate that even a dialysate containing 50 EU/L or less ET may stimulate monocytes and cause oxidative stress. They also suggest that even low levels of ET may aggravate arteriosclerosis in dialysis patients. Thus, in order to prevent cardiovascular events in dialysis patients, it is necessary to purify the dialysate.     

Captopril and ramiprilat protect against free radical injury in isolated working rat hearts

The protection of angiotensin converting enzyme (ACE) inhibitors, captopril and ramiprilat, against free radical-mediated myocardial injury were studied in isolated working rat hearts. Free radicals were generated by electrolysis of Krebs-Henseleit solution with 10 mA direct current for 1 min. Both captopril (360 μmol/l) and ramiprilat (12.5 μmol/l) significantly reduced the decrease of left ventricle dP/dt′_max, coronary flow (CF), myocardial superoxide dismutase (SOD) and creatine kinase (CK) activities and the elevation of S-T segment of epicardial ECG as well as the rise of myocardial malondialdehyde (MDA) content caused by electrolysed perfusate. Captopril afforded a dose-dependent protection on cardiac functions with various concentrations of 45, 90, 180 and 360 μmol/l. Iloprost (30 nmol/l), a stable mimetic of prostacyclin, could also alleviate free radical-mediated myocardial injuries. All the beneficial effects of ramiprilat (12.5 μmol/l) were abolished by the administration of indomethacin (5 μmol). In contrast, captopril (90 μmol/l) still exhibited significant protective effects after indomethacin (9 μmol) was administered, though these protective effects were insignificantly weakened. In order to assess the role of sulfhydryl (-SH) group in the effects of captopril, a SH-containing drug S8 and a disulfide DG4, both are deficient in ACE inhibitory properties in vitro, were examined. Data showed that S8 (180 μmol/l) provided a significant protection while DG4 showed no protective effect. It is concluded that ACE inhibitors can protect against free radical-induced myocardial damage. Ramiprilat, a non-SH-containing ACE inhibitor, inhibits free radical-induced damages mainly by stimulation of prostacyclin synthesis and/or release. In addition to this effect, captopril, a SH-containing ACE inhibitor, may exert additional anti-free radical effects by a mechanism which is probably related to the sulfhydryl group.