HSP70和NF-κB在大鼠肾缺血再灌注损伤中的表达及洛伐他汀的干预研究

目的探讨洛伐他汀(Lovastatin,Lov)对大鼠肾缺血再灌注损伤(RIRI)热休克蛋白70(HSP70)和核因子-κB(NF-κB)表达的影响。方法 90只Wistar大鼠随机分为3组:假手术(Sham)组、缺血再灌注模型(IR)组、洛伐他汀(Lov)组。IR组和Lov组大鼠采用夹闭肾动脉60 min后再灌注的方法制备RIRI模型,Lov组于动脉夹闭前给予洛伐他汀2mg/(kg d)灌胃,各组大鼠在再灌注4、12、24 h时分别处死10只取标本。测定各组大鼠的血肌酐(Scr)、尿素氮(BUN)水平,免疫组化法检测肾组织HSP70和NF-κB表达,镜下观察肾组织形态学改变。结果与Sham组大鼠相比,IR组大鼠在再灌注4、12、24 h时点的Scr和BUN含量均显著升高;肾组织HSP70和NF-κB表达均明显增强,差异均有统计学意义(P均<0.05)。与IR组相比,Lov组大鼠在各时点的Scr和BUN含量均显著降低(P均<0.01);HSP70表达均升高(P均<0.05);NF-κB表达减少,再灌注4、12 h时,两者差异有统计学意义(P<0.05);镜下病理改变减轻。结论 Lov可通过增加肾脏HSP70、下调NF-κB表达而抑制炎症反应过程,减轻肾脏损害,对大鼠RIRI起到一定的保护作用。     

缺血再灌注大鼠肾脏诱导型一氧化氮合酶表达的意义

目的观察缺血及缺血再灌注(IR)大鼠肾脏诱导型一氧化氮合酶(iNOS)表达变化的规律。方法制作大鼠肾脏缺血及IR模型,不同时间摘取肾脏,免疫组织化学法检测iNOS表达变化。HE染色观察肾脏损伤程度。结果缺血时及IR后iNOS表达均明显增强(P<0.05),且随时间呈一定的变化规律,呈先升高后下降趋势,24 h达峰值,72 h时降至2 h水平。结论肾脏缺血早期iNOS即起损伤作用,并于再灌注后加重损伤。     

二氧化硫预处理对心肌缺血再灌注损伤大鼠二氧化硫/天门冬氨酸氨基转移酶体系的影响

目的 探讨二氧化硫(SO2)预处理对心肌缺血再灌注损伤大鼠的保护作用及对心肌组织中SO2/天门冬氨酸氨基转移酶(AAT)体系的影响.方法　24只健康清洁级雄性Wistar大鼠随机分为假手术组、缺血再灌注组(I/R组)、SO2预处理组(I/R+S组).结扎大鼠左侧冠状动脉30 min,再灌注120 min,制备心肌缺血再灌注模型;I/R+S组大鼠在缺血前10 min用1 μmoL·kg-1SO2颈外静脉注射预处理.采用全自动生化检测仪检测大鼠血浆CK和LDH水平,用高效液相色谱法测定其心肌组织中SO2水平,采用蛋白免疫印迹法检测其心肌组织AAT1和AAT2蛋白表达水平.结果 缺血再灌注后,I/R组及IR+S组血浆CK、LDH水平均较假手术组明显增高(P＜0.01,0.05),I/R+S组血浆CK、LDH水平较I/R组均明显降低(Pa＜0.05).与假手术组比较,I/R组大鼠心肌组织匀浆中SO2水平显著降低(P＜0.05),I/R+S组无明显变化;I/R+S组SO2水平较I/R组显著增高(P＜0.01).I/R组大鼠心肌组织AAT1蛋白表达较假手术组显著降低(P＜0.01),I/R+S组与假手术组比较差异无统计学意义(P＞0.05),而I/R+S组AAT1蛋白表达则较I/R组显著增高(P＜0.01);AAT2蛋白表达在3组间的差异无统计学意义(P＞0.05).结论　SO2预处理可明显降低心肌缺血再灌注大鼠血浆中心肌酶活性,具有心肌保护作用,并对心肌组织中SO2/AAT体系具有上调作用.     

转化生长因子β1在大鼠心肌缺氧缺血再灌注损伤修复及心肌重塑中的作用

目的探讨内源性转化生长因子β1(TGF-β1)在心肌缺氧缺血—再灌注损伤修复及心肌重塑中的作用。方法根据新生鼠常压窒息模型,制作缺氧缺血—再灌注损伤大鼠动物模型,将60只新生大鼠随机分成缺氧缺血—再灌注损伤1d组(A组)、7d组(B组)、14d组(C组)以及正常对照组(D组)4组。每组15只用免疫组化方法对TGF-β1在心肌的分布及表达进行定性及半定量分析,用Masson染色方法测定心肌胶原容积(CVF),同时利用HE染色观察心肌组织的病理学改变。统计分析应用SPSS11·0统计软件进行。多组均数比较采用单因素方差分析,两变量之间的关系采用相关分析。结果TGF-β1表达:B组及C组分别与对照组相比,均有统计学意义(P均<0·01),胶原含量(CVF):B组及C组较正常对照组差异有统计学意义(P均<0·01),相关分析表明,CVF与TGF-β1之间呈正相关(r=0·574,P<0·01)。结论大鼠缺氧缺血—再灌注损伤后TGF-β1表达量随损伤时间不同而变化,其可能参与缺氧缺血—再灌注所致的内脏损伤后的自我修复。缺氧缺血—再灌注损伤后TGF-β1的表达与心肌胶原含量的变化呈正相关,提示TGF-β1可能参与损伤后心肌重塑。     

新生大鼠缺氧缺血性脑损伤氧化还原因子-1蛋白表达及意义的研究

目的：探讨新生大鼠缺氧缺血性脑损伤(HIBD)后,氧化还原因子-1 (APE/Ref 1)蛋白在大脑皮质不同时相的表达及其与神经细胞凋亡的关系。方法：将新生7日龄SD大鼠制成HIBD动物模型,采用免疫组织化学方法及原位缺口末端标记(TUNEL)法分别观察正常对照组、假手术组及缺氧缺血1, 3, 6, 12, 24, 48hAPE/Ref 1蛋白及神经细胞凋亡变化。结果：APE/Ref 1蛋白在正常对照组、假手术组神经细胞核内广泛表达,两组间差异无显著性(P>0. 05);而缺氧缺血组大脑皮质该蛋白表达随缺血时间的延长而下降,且各时间点间差异显著(P<0. 05)。大脑皮质凋亡阳性细胞表达与APE/Ref 1相反,其随缺血时间的延长逐渐增多,并在24h达到高峰,均高于正常对照组及假手术组(P<0. 05)。结论：新生大鼠脑组织缺氧缺血后,大脑皮质神经元APE/Ref 1蛋白表达减少, 凋亡细胞表达增加,提示APE/Ref 1蛋白减少和DNA修复功能失败可能与脑缺氧缺血后神经细胞的凋亡发生有关。     

二氧化硫预处理对大鼠离体心肌缺血再灌注损伤的保护作用

目的 探讨生理水平的二氧化硫(SO2)预处理对大鼠离体心肌缺血再灌注(I/R)损伤的保护作用,通过使用内质网应激抑制剂4-苯基丁酸(4-PBA)来探讨SO2预处理的作用机制.方法 应用Langendorff技术建立大鼠离体心脏灌注模型.将21只Wistar大鼠离体心脏随机分为3组:I/R组、SO2+I/R组及4-PBA+SO2+I/R组.通过Maclab采集系统监测心脏功能.记录缺血前30 min心功能指标,以缺血前离体心脏心率、左心室内压差、左心室内最大上升速率及最大下降速率为基础值,比较再灌注期间各组离体心脏各项心功能指标恢复率变化.结果 I/R可引起再灌注期间大鼠离体心脏心功能恢复率显著下降.经5 μmol·L-1SO2预处理后,相对于I/R组,再灌注期间大鼠离体心脏的各项心功能恢复率有不同程度的改善(Pa＜0.05),其中以左心室内压差、左心室内最大上升速率及最大下降速率改善最为明显.预先给予4-PBA持续灌流后,SO2预处理对大鼠I/R损伤的保护作用有不同程度的下降.相对于单纯SO2预处理组,4-PBA+SO2+I/R组再灌注30 min后左心室内最大上升速率及最大下降速率恢复显著下降.结论 SO2可能通过激活内质网应激反应发挥对大鼠I/R损伤的保护作用,4-PBA可部分逆转SO2预处理对于心脏I/R损伤的保护作用.     

血红素氧合酶-1在缺血再灌注大鼠肾脏的表达及意义

目的观察肾脏缺血及缺血再灌注(IR)大鼠诱导血红素氧合酶-1(HO-1)表达变化的规律。方法制作大鼠肾脏缺血及IR模型,不同时间摘取肾脏,免疫组织化学法检测HO-1表达变化。HE染色观察肾脏损伤程度。结果缺血30 min时HO-1明显升高(P<0.01)。IR后HO-1表达明显增强(P<0.01),且随时间呈一定变化规律。结论HO-1在缺血30 min及IR后表达增强,保护肾脏。     

钙敏感受体在大鼠心肌缺血/再灌注损伤中的作用

目的观察钙敏感受体在大鼠心肌缺血/再灌注损伤中的作用及其机制。方法30只Wistar大鼠随机分为3组(每组10只):假手术组(sham组)、缺血/再灌注组(I/R组)和钙敏感受体激动剂组(Gdcl3组),采用冠状动脉结扎和松结的方法,制备大鼠在体心肌缺血/再灌注损伤模型。分别测定血清一氧化氮(NO)、丙二醛(MDA)、超氧化物歧化酶(SOD)和乳酸脱氢酶(LDH)水平,光镜及透射电镜下观察心肌结构病理变化。结果I/R组血清LDH、MDA水平明显高于sham组(P<0.01),NO、SOD低于sham组(P<0..01);Gdcl3组血清LDH、MDA水平明显高于I/R组(P<0.01),而NO、SOD低于I/R组(P<0.01)。光镜及透射电镜下可观察到Gdcl3组心肌结构破坏,心肌细胞呈灶状或片状坏死;线粒体损伤,核皱缩,核染色质边集,其病理学改变程度较I/R组严重。结论钙敏感受体激活可使氧自由基产生增加,减少NO含量,降低SOD活性,加重心肌缺血/再灌注损伤。     

缺血再灌注损伤大鼠脑组织脑红蛋白表达的变化

目的探讨脑缺血再灌注损伤大鼠脑红蛋白(NGB)表达的变化与再灌注损伤时间的关系。方法建立大鼠脑缺血再灌注损伤动物模型,测定缺血再灌注损伤1h、4h、8h、16h、32h、64h、128h大脑皮质NGB表达的变化,对实验动物进行神经行为功能测试,并与假手术对照组进行比较。结果缺血再灌注损伤组与假手术组各时点比较,大脑皮层NGB阳性神经元呈现先上升后下降的趋势;而脑非缺氧性损伤侧神经元NGB阳性表达不随时间变化而改变。缺血再灌注损伤组缺血侧大脑皮层呈现延缓性脑梗死过程,各时间点组织切片显示缺血中心部位(纹状体和皮层外侧区)神经元损伤发生在缺血后8h,随着缺血时间的延长逐渐向半暗带区扩展,脑梗死灶逐渐扩大。再灌注1～128h,缺血侧缺血半暗带皮层NGB阳性神经元呈现先上升后下降的趋势,而非缺血侧对称区域皮层NGB阳性表达不随时间变化。缺血再灌注损伤后1h,缺血侧扣带皮层NGB阳性神经元数量无明显改变;再灌注损伤8～64h,在同一只大鼠脑组织缺血侧皮层NGB的表达与对侧NGB的表达存在显著差异:损伤8h,NGB阳性神经元数量开始增加(A=0.04±0.004P<0.05),损伤16h,NGB阳性神经元数量显著增加(A=0.06±0.003P<0.01),损伤32h达高峰(A=0.07±0.006P<0.05)。损伤64h,NGB阳性神经元数量显著减少(A=0.03±0.007P<0.05);损伤128h,缺血侧与非缺血侧扣带皮层NGB阳性神经元数量基本相当(A=0.04±0.006P>0.05),而脑非缺血侧脑组织NGB阳性细胞表达变化不大,各组间差异比较无统计学意义(P>0.05)。结论脑缺血再灌注损伤大鼠神经元NGB的表达变化呈现时间规律性,提示NGB对缺氧缺血性脑损伤有保护作用。     

胎鼠宫内缺血/再灌注损伤后细胞凋亡的分析

目的探讨凋亡在急性缺血/再灌注损伤中的作用。方法取孕21 d Wistar大鼠制成宫内缺血/再灌注损伤模型,取胎鼠肾组织行TUNEL分析凋亡细胞指数,免疫组化分析Caspase-3的表达。结果缺血5 min再灌注0 min、2 h、6 h、24 h肾组织凋亡细胞数分别为(12.99±0.18)%、(22.36±0.28)%、(22.73±0.56)%、(32.56±0.62)%和(18.57±0.35)%;再灌注2 h后,随着再灌注时间的延长,凋亡细胞数明显增加,与对照组(12.72±0.16)%比较,有显著差异(P<0.001);凋亡细胞指数以再灌注6h最高;Caspase-3的表达分别为(0.15±0.04),(0.30±0.04),(0.35±0.05),(0.30±0.03),(0.14±0.02),与对照组(0.10±0.03)比较,有显著差异(P<0.05),表达高峰于再灌注2 h出现。结论胎鼠宫内急性缺血再灌注损伤后,出现肾脏细胞不同程度的凋亡,伴有Caspase-3表达增强,Caspase-3表达比TUNEL能更早地反映细胞凋亡。     

新生大鼠缺氧缺血脑损伤后μ-calpain活化及其他相关因子表达变化的时程及意义

目的　探讨新生大鼠缺氧缺血性脑损伤 (HIBD)后脑内 μ calpain的活化、其他相关因子表达变化的时程及相互关系 ,进一步研究HIBD的发病机制。方法　HIBD模型采用改良的Rice法。应用Westernblot法半定量测定缺氧缺血 (HI)后 0、1、2、4、12和 2 4h大脑皮层和海马μ calpain、c Fos、c Jun、HSP70和HSP2 7的表达。蛋白浓度测定采用改良的Bradford法。结果　新生大鼠HI后 μ calpain裂解为 76和 80两个片段 ,两者比值在HI后显著提高 ,以海马更为明显 ,其中皮层在 2 4h、海马在 12h达到高峰。c Fos在HI后 2～ 12h海马显著高于皮层 (P <0 0 5 ) ,2 4h海马却低于皮层 (P <0 0 5 ) ;c Jun则 0～ 1h海马高于皮层 (P <0 0 5 ) ,4h以后皮层均高于海马 (P <0 0 5 ) (其中 12h差异无显著意义 )。c Fos和c Jun在HI后呈上升趋势 ,无论皮层或海马均在 2～ 4h达到高峰 ,以后渐下降 ,但 2 4h仍高于正常对照组。与对照组相比 ,c Fos在 1,2 ,4 ,12和 2 4h差异有显著意义 (P <0 0 5 ) ;c Jun在 0 ,1,2 ,4 ,12和 2 4h差异有显著意义 (P <0 0 5 )。HSP70在HI后 0h皮层显著高于海马 (P <0 0 5 ) ,1h海马显著高于皮层 (P <0 0 5 ) ,4h后皮层又均高于海马 (P <0 0 5 ) ;HSP2 7则HI后 1～ 2 4h海马均显著高于皮层 (P <0     

Maternal treatment with propofol attenuates lipid peroxidation after transient intrauterine ischemia in the neonatal rat brain

The purpose of this study was to investigate whether propofol has a neuroprotective effect on the fetal brain after intrauterine ischemia-reperfusion (I/R) injury in the rat fetus. Fetal brain ischemia was induced by clamping the utero-ovarian artery bilaterally for 30 min and reperfusion was achieved by removing the clamps for 2 h. A 40-mg/kg single dose of propofol was administered intraperitoneally 15 min before I/R injury. Lipid peroxidation in the brain tissue was determined as the concentration of thiobarbituric acid reactive substances (TBARS) for each fetal rat. Results showed that lipid peroxidation byproducts increased after I/R injury. Maternal treatment with propofol reduced TBARS compared to the I/R group. Propofol has been shown to have neuroprotective effects in intrauterine I/R-induced fetal brain damage in rats.     

The antifibrotic drug halofuginone reduces ischemia/reperfusion-induced oxidative renal damage in rats

AimThe objective of the present study was to evaluate the protective effects of halofuginone against renal ischemia/reperfusion (I/R) injury.Materials and methodsMale Wistar albino rats were unilaterally nephrectomized and the left renal pedicles were occluded for 45 min to induce ischemia and then reperfused for 6 h (early) or for 72 h (late). The rats were treated intraperitoneally with either halofuginone (100 μg/kg/day) or saline 30 min prior to ischemia and the dose was repeated in the late reperfusion groups. In the sham groups, rats underwent unilateral nephrectomy and were treated at similar time points. The animals were decapitated at either 6 h or 72 h of reperfusion and trunk blood and kidney samples were obtained.ResultsI/R injury increased renal malondialdehyde levels, myeloperoxidase activity and reactive oxygen radical levels, and decreased the renal glutathione content. Halofuginone treatment was found to reduce oxidative I/R injury and improve renal function in the rat kidney, as evidenced by reduced generation of reactive oxygen species, depressed lipid peroxidation and myeloperoxidase activity, and increased glutathione levels.ConclusionsThe present findings demonstrate the anti-inflammatory and antioxidant effects of halofuginone in renal I/R injury, supporting its potential use where renal I/R injury is inevitable.     

白藜芦醇对大鼠肠缺血再灌注损伤的保护作用

目的 探讨白藜芦醇(resveratro1,RES)对实验性大鼠肠缺血再灌注肠黏膜损伤的保护作用.方法 24只成年雄性SD大鼠随机分为假手术组(SO)、缺血再灌注损伤组(I/R)、RES治疗组.SO组仅分离肠系膜上动脉(SMA)根部而不夹闭.肠缺血再灌注损伤组(I/R)和RES治疗组均用无损伤血管夹夹闭SMA根部后分别立即经阴茎背静脉注射生理盐水、RES(20 mg/kg),45 min之后放松血管夹形成再灌注.各组大鼠均于制模后6 h采集标本.检测血清和回肠组织中的超氧化物歧化酶(SOD)和丙二醛(MDA)的含量,TUNEL法检测肠黏膜上皮细胞凋亡率,并观察肠黏膜病理变化.结果 小肠缺血再灌注后,血清及小肠组织中反映氧化损伤程度的MDA明显升高,SOD则明显减少,小肠黏膜上皮细胞凋亡,应用RES后能显著改善上述改变.结论 白藜芦醇对肠缺血再灌注损伤具有保护作用,其机制可能与通过抗氧化作用及抑制肠黏膜上皮细胞凋亡有关.

Abstract：

Objective To study the protective effects of resveratrol (RES) on intestinal ischemia-reperfusion injury in rats.Methods Twenty-four SD rats were randomly divided into the sham operation group,intestinal ischemia-reperfusion injury (I/R) group and resveratrol treated (RES) group.The intestinal ischemia injury was induced by superior mesenteric artery occlusion for 45 minutes,and then the blood supply to the intestine was restored to cause reperfusion injury.After 6 hours' reperfusion,the rats were sacrificed and intestine was collected.Of the RES group,the rats were subjected to I/R injury,and treated with 20 mg/kg resveratrol by intravenous injection immediately after the mesenteric artery was clamped.Superoxide Dismutase (SOD) and Malonaldehyde (MDA) levels in serum and intestine were measured.Apoptotic intestinal epithelial cells were detected by TUNEL methods.The histological injury of the intestine was also examined.Results Compared with the sham operated rats,MDA levels in the serum and intestine as well as the apoptotic epithelial cells were significantly increased in the rats subjected to I/R (MDA in serum and intestine 4.63±0.53 vs 1.32±0.40;8.60± 0.98 vs 4.13±0.86,P＜0.01;apoptotic index 66.63 ± 1.71 vs 46.72 ± 1.50,P＜0.01 ).However,the SOD levels in the serum and intestine were decreased (49.21±4.38 vs 86.65±6.14;351.03 ± 21.46 vs 468.93 ± 16.21,P＜0.01).In the rats subjected to I/R injury but received resveratrol treatment,the epithelial cells apoptosis and MDA levels in serum and intestine were decreased,and SOD levels in serum and intestine increased (P＜0.05).Conclusions Resveratrol protects intestine from ischemia-reperfusion injury in rats.     

β抑制蛋白2及微管相关蛋白轻链3在大鼠肾脏缺血再灌注损伤中的改变及意义

目的 探讨β抑制蛋白2(β-arrestin2)及微管相关蛋白轻链3(microtubule-associated protein light chain 3,LC3)在急性肾脏缺血再灌注损伤中的表达及与肾脏损害程度的相关性.方法 选用生后3~4周的雄性SD大鼠,随机分为正常组、假手术组、急性缺血再灌注损伤组.通过右侧肾脏切除,无创动脉夹夹闭左侧肾动脉45 min之后松开动脉夹,恢复肾脏血流,建立肾脏急性缺血再灌注损伤模型.并在恢复肾脏血流后12、24、36、48、72、96 h取肾脏及血液样本.采用免疫组织化学方法及West-ern blot方法检测各组肾组织中β-arrestin2及LC3蛋白的表达水平,检测各组的肾功能,并对各组肾脏病理学进行评分.结果 与正常组及假手术组相比,缺血再灌注损伤组血肌酐及肾脏病理学评分均有显著升高,其中肾脏损伤程度以缺血再灌注损伤后24 h最为明显;β-arrestin2及LC3蛋白在正常组及假手术组肾脏中的表达较少,在缺血再灌注损伤后的肾脏中表达显著升高,其中以缺血再灌注损伤后12 h时表达上调最为显著;β-arrestin2及LC3的表达改变先于肾脏病理改变,并且与肾脏损害程度呈正相关(r=0.821,P<0.05;r=0.913,P<0.05).结论 在肾脏急性缺血再灌注损伤时,β-arrestin2可能作为一个上游调控蛋白,通过对自噬的调节参与急性肾损伤的病理过程.     

脑缺氧缺血后热休克蛋白基因的表达及地塞米松对其的调节

目的　探讨热休克蛋白 - 70 (HSP70 )基因在缺氧缺血新生大鼠脑内的表达及地塞米松 (DEX)对其影响。方法　通过建立新生大鼠缺氧缺血性脑病动物模型 ,应用快速竞争性RT PCR技术 ,分别对缺氧缺血(HI) ,DEX预处理后予缺氧缺血 (DH) ,缺氧结束后即刻予DEX (HD) ,DEX加假手术 (DS) ,正常对照 (NS)五组动物的实验侧大脑组织中HSP70mRNA的表达进行半定量分析。结果　缺氧缺血后新生大鼠脑内HSP70mRNA的表达明显增强 ,其表达高峰 (3.86 8± 1.42 1)位于HI后 12h左右 ,并在 12～ 48h内维持较高水平 (3.186±0 .80 3,2 .5 6 8± 0 .70 9)。DEX预处理可使HSP70mRNA的表达明显下降或几乎完全被抑制 ,其 12h ,2 4h ,48h分别为 0 .5 2 6± 0 .5 93,0 .492± 0 .45 0 ,0 .434± 0 .42 8。HI后给予DEX对HSP70mRNA的表达则无明显影响。其12h ,2 4h ,48h分别为 3.46 0± 1.30 9,3.0 2 0± 0 .5 6 5 ,2 .2 42± 0 .5 0 4。结论　DEX预处理可抑制HI对HSP70mRNA过表达的诱导。推测DEX预处理后使HSP70mRNA的表达下降 ,可能与DEX抑制了神经元的过度兴奋有关。     

Orchiectomy or testosterone receptor blockade reduces intestinal mucosal damage caused by ischemia-reperfusion insult

The aim of the present study was to investigate whether orchiectomy or administration of flutamide an antagonist of the testosterone receptor can reduce oxidative stress and histologic damage in the rat small bowel subjected to mesenteric ischemia/reperfusion (I/R) injury. A total of 32 Sprague-Dawley rats were divided into four groups. Group 1 was control (sham), group 2 was I/R, group 3 was I/R plus orchiectomy (orchiectomy was performed 14 days before I/R), group 4 was I/R plus flutamide (flutamide was given throughout 14 days before mesenteric IR). Rats were subjected to 45 min of mesenteric ischemia followed by 3 h of reperfusion. The levels of ileal malondialdehyde (MDA) and nitric oxide (NO) were found to be significantly lower in orchiectomy and flutamide treatment groups compared with I/R group (P < 0.05). The histopathological injury scores were consistent with the MDA and NO levels. These results suggest that castration or testosterone receptor blockade decreases the level of intestinal I/R injury in male rats and it is an another example for disease variations based on gender differences.     

肾损伤分子-1在急性缺血缺氧再灌注大鼠肾组织中的表达及意义

目的 观察肾损伤分子-1(kidney injury molecule-1,KIM-1)在急性缺血缺氧再灌注肾损伤(acute ischemia reperfusion kidney injury,AIKI)大鼠肾组织中的表达及分布规律,探讨其在诊断急性肾损伤(acute kidney injury,AKI)中的价值.方法 采用清洁级SD大鼠128只,随机分为对照组和模型组,模型组按国际标准建立大鼠AIKI模型,分别于2h、6h、24h、48h、72h、1周、2周、4周处死(n=8),取肾组织,常规HE染色,参照Sayhan等标准对肾小管间质损伤进行半定量评分;免疫组织化学、Western blot法检测KIM-1蛋白的表达及分布;生化法测定血清肌酐(serum creatinine,Scr)水平.结果 (1)大鼠缺血再灌注后2h即出现明显肾小管间质损伤,随着再灌注时间延长损伤加重,48h达高峰后逐渐减轻,但仍高于对照组(P<0.01);(2)Western blot和免疫组织化学检测发现,缺血再灌注后2h肾组织KIM-1的表达明显升高,KIM-1表达水平与肾小管间质损伤评分呈显著正相关(r=0.887,P=0.003);(3)大鼠缺血再灌注后2h Scr明显升高,48h达到最高值后降至正常,其升高与肾小管间质损伤评分无相关性(r=0.280,P=0.502).结论 AIKI模型中大鼠肾组织KIM-1蛋白表达水平显著增加,其表达水平与肾小管间质损伤评分呈正相关,与Scr相比,KIM-1可能为更准确地反映肾损伤情况的指标.     

Reduced apoptosis in newborn compared to adult rat intestine after ischemia-reperfusion injury

The pathogenesis of necrotizing enterocolitis (NEC) is unknown. Ischemia and reperfusion (I/R) injury has been considered to be a major contributing factor. More recent reports have noted that apoptosis is a significant and perhaps the principal contributor to cell death after I/R. Some reports revealed that infants with NEC and perforated bowel can completely recover with drainage alone. This study aims to assess the ability of newborn rat intestine to resist apoptosis after I/R injury compared with adult rat intestine. Intestines from 10 groups of rats (n = 6 for each study group) were studied: (1) normal control group; (2) ischemia group, receiving vascular occlusion for 60 min; (3) I/R groups receiving vascular occlusion for 60 min and reperfusion for 15, 30, and 60 min, respectively. Apoptosis was quantified by TUNEL methods. Statistical analysis was performed using ANOVA with Dunn's test. TUNEL-positive cells per 10 crypts were significantly increased in the ischemia and I/R groups compared to the control group. The peak number of positive cells by TUNEL was recognized 30 min after reperfusion in adult and newborn rats and then reduced gradually. The newborn rats had significantly less TUNEL-positive cells per 10 crypts than adult rats subjected to I/R injury (p < 0.05). We demonstrated that the activation of apoptosis occurred after intestinal I/R injury, especially during the reperfusion phase. The newborn intestine was more resistant to I/R injury and thus may have significant clinical application.