胰高血糖素样肽-2对小鼠小肠缺血/再灌注损伤的保护作用

目的:观察胰高血糖素样肽-2(GLP-2)对缺血/再灌注损伤小鼠小肠的保护效应.方法:采用肠缺血/再灌注(I/R)模型,将32只小鼠随机分为4组(n=8)假手术(Sham)组、I/R组、I/R GLP-2保护组和I/R 谷氨酰胺(GLN)阳性对照组.光镜观察小肠黏膜形态学改变.检测小肠绒毛高度和隐窝深度;小肠组织二胺氧化酶(DAO)活性;肠系膜淋巴结(MLN)细菌易位率.结果:与假手术组相比,I/R组部分小肠绒毛坏死脱落,绒毛高度下降,隐窝变浅(P＜0 01);小肠组织DAO活性降低(P＜0.01);MLN细菌易位率增加(P＜0.05).与I/R组比,GLP-2组肠绒毛损害明显减轻,DAO活性回升(P＜0.01),细菌易位率回降(P＜0.05).结论:GLP-2对缺血/再灌注损伤小鼠小肠的形态结构及肠屏障功能具有保护作用.     

兔肠缺血／再灌注损伤的超微结构改变及红花的保护作用

目的：观察红花注射液对兔肠缺血／再灌注损伤超微结构的影响,探讨其机制。方法：复制在体兔肠缺血／再灌注损伤模型。30只日本大耳兔,随机均分为3组（n=10）：假手术组（S组）,缺A／再灌注组（I／R组）和缺血／再灌注＋红花注射液组（SI组）。使用电镜观察各组肠组织标本超微结构的改变,作对比分析。结果：L／R组多数肠粘膜上皮细胞肿胀,胞质内液泡增多,大多数线粒体呈不同程度的肿胀,严重者可见嵴减少或消失,内质网扩张较明显,细胞表面微绒毛数量明显减少且排列较乱,部分微绒毛有肿胀、融合现象,上皮细胞间隙扩大,连接较疏松。粘膜下间质可见少量的浆细胞浸润现象,部分毛细血管周围可见水肿现象。SI组在上述部位的病理改变均明显减轻。结论：红花能有效减少炎性渗出,抑制微循环通透性的增加,阻断肠缺血／再灌注损伤进展的病理生理过程,对肠组织超微结构有良好保护作用。     

胰岛素对大鼠肠缺血再灌注损伤的影响

目的:观察胰岛素对大鼠肠缺血再灌注后小肠组织损伤的影响。方法:雄性SD大鼠40只随机分为4组,每组10只,手术对照组、单纯缺血组、再灌注组、胰岛素干预组。于30min缺血和120min再灌注后,进行组织病理学和生化检测。结果:(1)单纯缺血组肠粘膜损害较手术对照组明显升高(P<0.01),超氧化物歧化酶(SOD)活性无明显变化;(2)再灌注组SOD活性明显降低,与手术对照组和单纯缺血组相比较差异均有显著性(P<0.01);(3)胰岛素组SOD活性与再灌注组相比有明显改善(P<0.01)。结论:肠缺血可以引起肠粘膜损伤,再灌注则可加重这种损伤,胰岛素可以减轻再灌注损伤。     

乌司他丁对肠缺血-再灌注大鼠血清TNF—α，IL-6的影响

目的：通过检测血清TNF-α,IL-6的变化,评价乌司他丁对小肠缺血再灌注损伤的保护作用及机制。方法i健康Wistar大鼠84只,通过夹闭肠系膜上动脉（SMA）60min制作肠缺血模型,随机分成假手术组（C）,肠缺血再灌注组（I）,UTI治疗组（u）。根据缺血后再灌注时间不同又将I组和U组分成0min、2h和6h组。I组、U组于手术前经尾静脉分别注入生理盐水2mL、乌司他丁5×10^4U／kg,假手术组仅分离SMA,不夹闭血管。于各时点取腹主动脉血测定血清TNF-α、IL-6含量。结果：肠缺血再灌注各时相点均引起血清TNF-α、IL-6的变化,与假手术组相比,各时点TNF-α值显著升高（P〈0．01）,IL-6显著升高（P〈0．01）。u组0min、2h血清TNF-α值低于相应时点的I组（P〈0．01）;U组0min、2h、6h血清IL-6值低于相应时点的I组（P〈0．05）。结论：乌司他丁可减轻小肠缺血再灌注后的炎症反应。     

缺血再灌注对大鼠肾脏足细胞podocin的表达影响及意义

目的:观察SD大鼠缺血再灌注肾损伤足细胞表面相关蛋白(podocin)表达的变化,探讨podocin分子在足细胞损伤中的作用.方法:60只雄性SD大鼠随机分为假手术组(S组)30只和模型组(M组)30只,各组又分为lh、3h、6h、12h、24h、48h六个亚组,每个亚组各5只.采用Westemblot蛋白印迹法检测肾皮质足细胞podocin蛋白表达.并观察各组血肌酐、尿素氮的变化.结果:与S组相比,肾缺血再灌注损伤后,M组尿素氮于6h开始升高,且48h达高峰(P＜0.05);血肌酐48 h才升高(P＜0.05).Podocin 蛋白在3h表达开始下降,以后随缺血再灌注时间的延长podocin蛋白的表达逐渐下降,且48h组下降最明显(P＜0.01).结论:(1)缺血再灌注肾损伤时大鼠肾功明显发生改变,尿素氮早期开始升高,血肌酐晚期升高明显,说明造模成功.(2)大鼠肾脏足细胞podocin的蛋白表达随着缺血再灌注时间的延长而改变,早期下降不明显,3h组开始逐渐下降,48h组下降最明显.此结果表明podocin蛋白在肾脏缺血再灌注肾损伤表达减少.我们可以推想在缺血再灌注肾损伤时,podocin随缺血时间延长而表达逐渐减少的同时,也破坏了与足细胞相关蛋白之间的联系,这种关系的破坏最终导致足细胞受损.通过对足细胞表面蛋白podocin的研究,对将来肾脏足细胞损伤的防治提供新的思路.     

虎杖甙抗肺缺血/再灌注损伤作用及其机制初探

目的：探讨虎杖甙（PD）抗肺缺血/再灌注损伤作用及其机制。方法：采用在体兔单肺原位缺血/再灌注损伤模型。健康日本大耳白兔40只随机均分成4组（n=10）：假手术对照组（C组）;肺缺血/再灌注组（I/R组）;肺缺血/再灌注＋虎杖甙组（PD组）,缺血前20 min和再灌注即刻按2.5 mg/kg静脉注射0.2%PD溶液;肺缺血/再灌注＋PD＋多粘菌素B组（PMB组）,给PD同时按24 mg/kg静注PMB。各组分别在缺血前20 min,缺血1 h即刻,再灌注1 h、2 h、3 h各时点颈动脉抽血检测丙二醛（MDA）含量,超氧化物歧化酶（SOD）活性。实验结束时,取肺组织测湿干重比（W/D）,计算肺泡损伤率（IAR）,电镜观察细胞超微结构改变。结果：①I/R组和PMB组血清SOD活性随着缺血和再灌注时间的延长而逐渐下降,且两组间无差异;PD组则显著改善（均P〈0.01）。②I/R组、PD组、PMB组血清MDA浓度均随着缺血和再灌注时间的延长而逐渐上升,但PD组上升明显缓慢（均P〈0.01）。③I/R组、PD组和PMB组的W/D与IAR均高于C组（P〈0.05或P〈0.01）,但PD组显著低于I/R组和PMB组（均P〈0.01）。④I/R组及PMB组肺组织的超微结构损伤严重,PD组损伤程度明显较轻。结论：PD对肺缺血/再灌注损伤具有拮抗作用,其机制除抗氧化损伤外可能还有PKC参与。     

血清NGAL 在大鼠肾脏缺血再灌注损伤不同时段 的表达及其意义

目的:观察大鼠肾脏缺血再灌注损伤不同时段血中性粒细胞明胶酶相关脂质运载蛋白(NGAL)的表达并探讨其在急性肾脏缺血再灌注损伤中的意义.方法:建立大鼠肾脏缺血再灌注损伤模型,将50只大鼠随机分为假手术组(S组)和模型组(M组),每组分为5个亚组,包括2h、6h、12h、24h、48h,每亚组大鼠5只.观察各组血NGAL,β2-微球蛋白及血尿素氮,肌酐的变化.结果:M组血NGAL于再灌注损伤后早期(2h)即开始升高,于24h达高峰,至48h仍高于正常(P＜0.05);β2-微球蛋白于12h升高至48h达高峰(P＜0.01);尿素氮于6h升高于48h达高峰(P＜0.01);而血肌酐则于48h才显著升高(P＜0.05).病理显示:M组2h时可见受损肾小管上皮细胞肿胀,管腔扩张、刷状缘消失,至6h时少量上皮细胞脱落、变性甚至坏死,管腔内可见坏死脱落的细胞碎屑,蛋白管型出现,12h时可见间质水肿压迫至管腔明显狭窄,于24h、48h可见蛋白管型显著增多.结论:血NGAL可作为肾脏缺血再灌注损伤早期敏感的生物标志物.     

胰岛素对大鼠肠缺血再灌注损伤的影响

目的：观察胰岛素对大鼠肠缺血再灌注后小肠组织损伤的影响。方法：雄性SD大鼠40只随机分为4组,每组10只,手术对照组、单纯缺血组、再灌注组、胰岛素干预组。于30min缺血和120min再灌注后,进行组织病理学和生化检测。结果：（1）单纯缺血组肠粘膜损害较手术对照组明显升高（P〈0.01）,超氧化物歧化酶（SOD）活性无明显变化;（2）再灌注组SOD活性明显降低,与手术对照组和单纯缺血组相比较差异均有显著性（P〈0.01）;（3）胰岛素组SOD活性与再灌注组相比有明显改善（P〈0.01）。结论：肠缺血可以引起肠粘膜损伤,再灌注则可加重这种损伤,胰岛素可以减轻再灌注损伤。     

对淤血再灌注肠神经组织损伤机制的探讨

目的:建立大鼠肠淤血再灌注动物模型,探讨淤血再灌注肠神经组织损伤的机制,为临床相关疾病的诊断、治疗提供理论依据.方法:成年Wistar大鼠60只,雌雄不限,随机分为正常组、对照组和实验组,每组20只.实验组采用阻断门静脉1h后开放的方法建立大鼠小肠淤血再灌注模型,对照组只进行同样腹部手术操作但不夹闭门静脉,正常组不手术.6小时后取各组下腔静脉血,测定血清中超氧化物歧化酶(SOD)活性和丙二醛(MDA)的含量,然后处死动物,取距回盲部15厘米处肠管1厘米,采用伊红-苏木素(HE)染色观察肠粘膜组织形态学变化;用免疫组织化学方法观察正常组、对照组和实验组小肠壁肠神经组织中微管相关蛋白2(MAP-2)的表达情况.结果:HE染色可见,正常组、对照组为正常肠道管壁结构,实验组肠壁各层有比较明显的淤血、出血,小肠绒毛固有层水肿,黏膜上皮有脱落、坏死;实验组MAP-2的表达明显低于正常组及对照组(P＜0.05);与正常组及对照组相比较,实验组SOD活性明显降低(P＜0.05),MDA的含量则明显升高(P＜0.05).结论:肠淤血再灌注可能导致肠道神经元数量减少,其机制可能与肠淤血再灌注造成的自由基损伤和脂质过氧化有关.     

川芎嗪联用L-精氨酸对缺血/再灌注损伤兔心肌线粒体功能的影响

探讨川芎嗪联用L-精氨酸对心肌缺血／再灌注损伤（MI／RI）时心肌细胞线粒体功能的影响。方法：选用日本大耳白兔50只,随机分为正常对照组（A组）、心肌缺血／再灌注组（B组）、心肌缺血／再灌注＋川芎嗪治疗组（C组）、心肌缺血／再灌注＋L-精氨酸治疗组（D组）和心肌缺血／再灌注＋川芎嗪＋L-精氨酸治疗组（E组）。观察心肌线粒体呼吸功能、Ca^2＋浓度（[Ca^2＋]m）、丙二醛浓度（MDA）、超氧化物歧化酶活性（SOD）和心肌组织三磷酸腺苷（ATP）、能荷（EC）的变化。结果：C、D、E组与B组比较,线粒体呼吸控制率（RCR）、Ⅲ态呼吸速率（ST3）、SOD明显升高,Ⅳ态呼吸速率（ST4）、[Ca^2＋]m、MDA显著降低,心肌组织ATP、EC均明显增高;且与A组比较,E组上述指标均无明显差异。结论：川芎嗪联用L-精氨酸可通过降低氧自由基水平和减轻钙超载,而改善缺血／再灌注损伤心肌的线粒体功能。     

Hydrogen-rich saline protects against intestinal ischemia/reperfusion injury in rats

Hydrogen gas was reported to reduce reactive oxygen species and alleviate cerebral, myocardial and hepatic ischemia/reperfusion (I/R) injuries. This paper studied the effect of hydrogen-rich saline, which was easier for clinical application, on the intestinal I/R injury. Model of intestinal I/R injury was induced in male Sprague-Dawley rats. Physiological saline, hydrogen-rich saline or nitrogen-rich saline (5 ml/kg) was administered via intravenous infusion at 10 min before reperfusion, respectively. The intestine damage was detected microscopically and was assessed by Chiu score system after I/R injury. In addition, serum DAO activity, TNF-α, IL-1β and IL-6 levels, tissue MDA, protein carbonyl and MPO activity were all increased significantly by I/R injury. Hydrogen-rich saline reduced these markers and relieved morphological intestinal injury, while no significant reduction was observed in the nitrogen-rich saline-treated animals. In conclusion, hydrogen-rich saline protected the small intestine against I/R injury, possibly by reduction of inflammation and oxidative stress.     

奥曲肽治疗急性粘连性肠梗阻疗效观察

目的:探讨生长抑素对腹部手术后急性粘连性肠梗阻的治疗作用。方法:70例急性粘连性肠梗阻患者随机分为观察组与对照组各35例。对照组予胃肠减压、灌肠、补液及抗感染治疗等常规治疗;观察组在此基础上加用奥曲肽(生长抑素类似物)0.1 mg皮下注射,每8h一次,治疗72 h。观察两组患者腹痛评分、腹痛缓解时间、胃肠减压量、肛门恢复排气时间、立卧位腹部平片、临床缓解情况。结果:观察组34例(97.1%)临床缓解,明显高于对照组的28例(80.0%)(P<0.05)。与对照组相比,观察组在治疗第1、2天后腹痛评分明显下降(均为P<0.01),腹痛缓解时间显著缩短(P<0.01),治疗第1、2、3天的胃肠减压量均显著减少(均为P<0.01),恢复排气时间也明显缩短(P<0.01)。结论:急性粘连性肠梗阻在常规治疗基础上加用生长抑素,可明显改善临床症状,提高疗效。     

PCT及CRP在急性肠梗阻大鼠血清中的表达水平及其临床意义

目的:探讨降钙素原(Procalcitonin,PCT)及C反应蛋白(C-reactive protein,CRP)在急性肠梗阻大鼠血清中的水平及其临床意义。方法:将83只Wistar大鼠分为对照组(n=13)、假手术组(n=35)和急性肠梗阻组(n=35)。对照组大鼠采集标本后处死,肠梗阻组行开腹手术结扎回肠末端,假手术组仅行开腹手术。检测8 h、24 h、48 h、72 h及96 h血清PCT及CRP水平,观察急性肠梗阻大鼠回肠组织的病理学改变情况。结果:假手术组PCT与CRP水平在术后24 h内显著升高,48 h至96 h逐渐下降;各时间点PCT水平明显高于对照组,而CRP水平在实验结束时已恢复至正常水平。肠梗阻组PCT和CRP水平在各时间点均明显高于对照组,并逐渐增加,到实验结束时达到高峰;肠梗阻组PCT和CRP水平在48 h-96 h均显著高于假手术组,差异具有统计学意义(P0.05)。组织病理学检查显示,对照组大鼠肠壁粘膜结构正常,假手术组可见轻度病理改变,肠梗阻组大鼠回肠组织可见粘膜结构明显破坏,绒毛坏死,严重水肿和炎症细胞浸润。结论:血浆PCT和CRP水平能够反映肠梗阻的状态和肠粘膜受损程度。     

Detection of early stages of apoptosis in experimental intestinal ischemia-reperfusion injury

Apoptosis is a form of programmed cell death that plays an important role in small intestine ischemia-reperfusion (IR) injury. The aim of this study was to determine the total proportion of apoptotic cell death (apoptotic index) following injury induced by ischemia and during various subsequent reperfusion periods, total histopathological status and the intestine regeneration dynamics after the IR injury. Experimental animals, Wistar rats (n = 45) were divided into three experimental and one control groups. In the experimental groups 1 h ischemia was followed by 1, 4 and 24 h reperfusion. Intestinal ischemia was induced by superior mesenteric artery (SMA) occlusion. Segments of jejunum were stained with hematoxylin and eosin and studied immunohistochemically using M30 CytoDEATH and in situ TUNEL methods for apoptosis detection. Our experimental data showed that: (i) apoptosis is an important form of cell death in the small intestine after IR injury induced by SMA occlusion; (ii) maximum levels of histopathological damage and apoptotic index of mucosa occurred after 1 h ischemia and 1 h of reperfusion; and (iii) mucosa possesses great regeneration ability. The lowest levels of histopathological damage and apoptotic index were observed in the group with 1 h ischemia and 24 h reperfusion where, however, the highest mitotic index was present.     

Brief small intestinal ischemia lessens renal ischemia-reperfusion injury in rats

Ischemic preconditioning (IPC) not only reduces local tissue injury caused by subsequent ischemia-reperfusion (IR) but may also have a beneficial effect on IR injury of tissues remote from those undergoing preconditioning. In this study, we investigated the effect of small intestinal IPC on renal IR injury in rats. Renal IR injury was induced by a 45-min renal artery occlusion and reperfusion for 2 or 24 h in rats with a previous contralateral nephrectomy, and ischemic preconditioning was induced by 3 cycles of 8-min ischemia and 5-min reperfusion of the small intestine. We then measured the concentrations of plasma creatinine (Cr) and blood urine nitrogen (BUN) and the level of malondialdehyde (MDA) and activities of superoxide dismutase (SOD) and catalase (CAT) in the renal cortex. Renal histopathology also was evaluated. Pretreatment with intestinal ischemic preconditioning significantly alleviated renal IR injury, as shown by decreases in the levels of Cr, BUN, and MDA, decreased renal morphologic change, and improved preservation of SOD and CAT activities. These results suggest that remote ischemic preconditioning of the small intestine protects against renal IR injury by inhibition of lipid peroxidation and preservation of antioxidant enzyme activities.     

脑利钠肽后处理对兔急性心肌梗死的保护作用

目的：脑利钠肽后处理对兔急性心肌梗死的保护作用及可能机制。方法：30 只兔随机分为3 组,每组10 只,左冠状动脉的左 室支缺血30 分钟,再灌注120 分钟。AMI（急性心肌梗死）组：再灌注期间静脉滴注生理盐水;BNP（脑利钠肽）组：再灌注期间静脉 滴注rhBNP(重组人脑利钠肽);BNP+GLY（脑利钠肽+格列苯脲）组：再灌注期间静脉滴注rhBNP,同时舌下静脉注射GLY 。连续 监测心电变化,统计再灌注120 min 室性心动过速(VT)、心室颤动(VF)的发生率。心肌再灌注120 min 后,分别测定SOD(超氧化 物歧化酶)、MDA（丙二醛）、cTnI（肌钙蛋白I）、CK-MB（肌酸激酶同工酶）。各组随机抽取2 只兔,分别于再灌注1 小时和2 小时末 取心尖组织,HE 染色。结果：（1）再灌注心律失常：BNP 组与AMI组比较,VT 和VF发生率均明显升高（均为P<0.01）;BNP+GLY 组与BNP 组比较,VT 和VF 发生率均明显升高（均为P<0.01）。（2）SOD、MDA、cTnI 和CK-MB 水平：BNP 组与AMI 组比较, MDA、cTnI 和CK-MB 均明显降低（均为P<0.01）,而SOD 明显升高（P<0.01）;BNP+GLY 组与BNP 组比较,MDA、cTnI 和 CK-MB 均明显升高（分别为P<0.01,P<0.05和P<0.01）,而SOD明显降低（P<0.01）。（3）心肌HE 染色：AMI组和BNP+GLY 组心 肌损伤明显,BNP 组心肌损伤轻微。结论：脑利钠肽后处理对兔急性心肌梗死（缺血- 再灌注损伤）具有保护作用,可能与KATP 通道相关。     

Intestinal reperfusion injury is mediated by IgM and complement.

Intestinal ischemia-reperfusion injury is dependent on complement. This study examines the role of the alternative and classic pathways of complement and IgM in a murine model of intestinal ischemia-reperfusion. Wild-type animals, mice deficient in complement factor 4 (C4), C3, or Ig, or wild-type mice treated with soluble complement receptor 1 were subjected to 40 min of jejunal ischemia and 3 h of reperfusion. Compared with wild types, knockout and treated mice had significantly reduced intestinal injury, indicated by lowered permeability to radiolabeled albumin. When animals deficient in Ig were reconstituted with IgM, the degree of injury was restored to wild-type levels. Immunohistological staining of intestine for C3 and IgM showed colocalization in the mucosa of wild-type controls and minimal staining for both in the intestine of Ig-deficient and C4-deficient mice. We conclude that intestinal ischemia-reperfusion injury is dependent on the classic complement pathway and IgM.