地尔硫及过氧岐化酶对心肌缺血再灌注损害的保护

目的 :对比地尔硫 (DTZ)及过氧岐化酶 (SOD)对心肌缺血再灌注损害的保护作用 ,以及明确联合应用 SOD+DTZ的疗效是否比单一药物更好。方法 :将 37只小型猪造成在体心肌缺血再灌注模型 ,分为 4组。 组 10只于再灌注前5分钟经静脉注射生理盐水作为对照组 , 组 9只再灌注前 5分钟静脉注射 SOD, 组 8只于再灌注前 5分钟静脉注射 DTZ, 组 9只于再灌注前 5分钟静脉注射 DTZ+SOD。结果 :(1)心梗范围 :用药各组与对照组比较 ,均有显著性缩小 ,DTZ+SOD组与 SOD组及 DTZ组比较 ,时性均有显著缩小 ;(2 )心肌钙离子含量 :SOD组与对照组比较有降低 ,但无显著性差异 ,而 DTZ组及 SOD+DTZ组与对照组比较均有显著的降低 ;(3) DTZ组及 SOD+DTZ组均可降低心率 ,减少再灌注性心律失常 ;(4)用药组均有降低灌注后 CK- MB的作用 ,但 SOD组的降低效果不明显 ,与对照组比较 ,无显著差异 ,而 DTZ组与对照组比较时性有显著性降低 ;SOD+DTZ组与 SOD组及 DTZ组比较均有显著性降低 ;(5 )电镜心肌超微结构观察显示 :心肌细胞损伤程度对照组比用药组严重 ,SOD组比 DTZ组及 SOD+DTZ组严重 ,DTZ组比 SOD+DTZ组严重。结论 :SOD、DTZ对缺血再灌注心肌有明确的保护作用 ,但 DTZ效果优于 SOD,合用 SOD+DTZ较应用其中单一药物效果更好。

妊高征患者血清过氧化物岐化酶的变化及其意义

测定了25例妊娠高血压综合征(妊高征)患者血清人过氧化物岐化酶-1(hSOD-1)含量。结果表明重度妊高征患者血清hSOD-1含量为851.62±70.97mg/L,显著高于正常对照、正常妊娠组及轻、中度妊娠高征组(分别为148.84±60.53mg/L,894.12±122.21mg/L和390.12±26.15mg/L)(P<0.01)。有肝、肾功能损伤者,血清hSOD-1明显高于无肝、肾操作者(P<0.001)对12例患者动态观察发现产前血清hSOD-1含量明显高于产后24小时血清hSOD-1含量(分别为709.35±72.78mg/L与343.42±33.10mg/L,P<0.001)。还发现妊高征患者血清hSOD-1含量与外周血白细胞计数量显著正相关(r=0.5015,P<0.02)。提示氧自由基可能参与了妊高征的发病,而血清hSOD-1的增高可能与中性粒细胞释放自由基有关。

血清过氧歧化酶活力测定在消化道肿瘤诊断中的作用

应用黄嘌呤氧化酶法测定９３例各种消化道肿瘤病人及４６例正常献血员的血清过氧歧化酶的活力，发现各种消化道肿瘤病人的血清ＳＯＤ活力明显降低。４６例正常成年人血清ＳＯＤ活力为１３２．９±２０．０１（ｕ／Ｌ），其中男２１例，为１３３．０７±２２．３（ｕ／Ｌ），女２５例为１３２．７±１８．３５（ｕ／Ｌ），男女组间差异无显著性。９３例各消化道肿瘤病人的血清ＳＯＤ活力为１００．２７±２０．８３（ｕ／Ｌ），和正常人相比，差异有高度显著性（Ｐ＜０．０１）。

温度环境和活性氧的应激反应

逐渐明确了活性氧对各种生命现象的参与。过氧岐化酶(SOD)的异酵素之一的Mn-SOD是由于受各种刺激和应激而诱导,来增加组织的酶浓度,而对活性氧应激防御承担着重要功能。本文就已往几乎不清楚的Mn-SOD浓度对寒冷、暑热的影响为中心介绍温度环境所致活性氧消除系统的变化。

Studies on the Anti-lipid Peroxidative Actions of the Methanolic Extract of the Root of Aegle marmelos and Its Constituents In Vivo and In Vitro

The inhibitory effect of the methanolic extract of the root of Aegle marmelos (MERA) and its constituents on the lipid peroxidation in vivo and in vitro were studied. The results suggested that MERA increased the activities of superoxide dismutase (SOD) and GSH-peroxidase in the liver cytosol of mice, but showed no significant effect on the activity of catalase, and one of its major constituents, 4-methoxy-1-methyl-2-quinolone (MMQ) increased the activity of SOD in liver tissue of mice intoxicated with FeCl2-ascorbic acid (AA)-ADP in vivo. Various constituents isolated from the root of title plant inhibited the lipid peroxidation in rat liver homogenate, which was in vitro induced by FeCl2-ascorbic acid, CCl4-NADPH, or ADP- NADPH. Of the test compounds, MMQ and its derivatives integriquinolone were similar to (-tocopherol in inhibiting MDA production in rat liver microsomes induced by Fe2+-ascorbate, CCl4-NADPH, or ADP-NADPH.

Effect of salt stress on activity of superoxide dismutase （SOD） in Ulmus pumila L.

The injury tolerance of cell plasma membrane and the correlative enzymes activities of plasma-membrane protection system in the Ulmuspumila leaves treated by nine concentrations （0.3%, 0.6%, 0,9%, 1,2%, 1.5%, 1.8%, 2,1%, 2.4%, 3.0%） of Na2CO3 and NaHCO3 mixtures were studied in a greenhouse of Northeast Forestry University, Harbin, China. The rate of electrolyte leakage （REL） and SOD （Superoxide dismutase） activity in leaves of different samples were determined. Results showed that the REL in leaves of U. pumila presented a slowly increasing trend at the salt concentrations less than 1.5%, which indicated that cell plasma membrane of U. pumila leaves had rather strong resistance to the injury of salt ion, and had a significant increase at the salt concentrations more than 1.5%. The SOD activities in leaves of U, pumila presented an increased trend at salt concentrations less than 1.5%, the growth of seedlings did not decline, and tress and leaves had no symptom of injury, while the salt concentrations exceeded 1.5%, SOD activities sharply decreased and REL increased promptly.

Superoxide dismutase prevents development of adenocarcinoma in a rat model of Barrett's esophagus

AIM： To test whether antioxidant treatment could prevent the progression of Barrett＇s esophagus to adenocarcinoma. METHODS： In a rat model of gastroduodenoesophageal reflux by esophagojejunal anastomosis with gastric preservation, groups of 6-10 rats were randomized to receive treatment with superoxide dismutase （SOD） or vehicle and followed up for 4 too. Rat＇s esophagus was assessed by histological analysis, superoxide anion and peroxinitrite generation, SOD levels and DNA oxidative damage. RESULTS： All rats undergoing esophagojejunostomy developed extensive esophageal mucosal ulceration and inflammation by mo 4. The process was associated with a progressive presence of intestinal metaplasia beyond the anastomotic area （9% 1st mo and 50% 4th too） （94% at the anastomotic level） and adenocarcinoma （11% 1^ST mo and 60% 4th too）. These changes were associated with superoxide anion and peroxinitrite mucosal generation, an early and significant increase of DNA oxidative damage and a significant decrease in SOD levels （P〈0.05）. Exogenous administration of SOD decreased mucosal superoxide levels, increased mucosal SOD levels and reduced the risk of developing intestinal metaplasia beyond the anastomotic area （odds ratio = 0.326; 95%CI： 0.108-0.981; P = 0.046）, and esophageal adenocarcinoma （odds ratio = 0.243; 95%CI： 0.073-0.804; P = 0.021）. CONCLUSION： Superoxide dismutase prevents the progression of esophagitis to Barrett＇s esophagus and adenocarcinoma in this rat model of gastrointestinal reflux, supporting a role of antioxidants in the chemoprevention of esophageal adenocarcinoma.

Inhibition effect of expression of Cu/Zn superoxide dismutase from rice on synthesis of Glutathione in Saccharomyces cerevisiae

The expression of a rice Cu/Zn superoxide dismutase （Cu/Zn-SOD） in Saccharomyces cerevisiae regulated by GAPDH promoter, involved in the inhibition of endogenous Glutathione （GSH） synthesis, and the competitive expression was detected by constructing the expression vector transferred Cu/Zn-SOD gene into wild-type S. cerevisiae. Transcription and expression of the Cu/Zn-SOD gene in S. cerevisiawere were confirmed by northern blot and SDS-PAGE, respectively, and activity of the Cu/Zn-SOD from crude extracts was enzymatically detected based on the effect of nitroblue tetrazolium （NBT） after running a native polyacrylamide gel. The GSH synthesis was also tested by DTNB （5, 5＇-Dithiobis （2-nitrobenzoic acid）） method. Results showed that GSH synthesis was evidently suppressed by the expression of Cu/Zn-SOD gene in both control and heat shock strains. It implied that the expression of the Cu/Zn-SOD gene in S. cerevisiae has more potential facility in response to oxidative exposure than that of endogenous GSH, although Cu/Zn-SOD and GSH were both contributed to the function of oxygen radical oxidoreduction.