不同营养方式对肠道缺血再灌注大鼠肠屏障功能的影响

目的探讨不同营养物质及支持途径对肠道缺血再灌注大鼠肠屏障功能和细菌易位的影响。方法60只雄性SD大鼠建立肠道缺血再灌注模型,随机分成普通肠外营养组(PN),富含谷氨酰胺的肠外营养组(G-PN),普通肠内营养组(EN)及免疫增强型肠内营养组(IEN)。从术后第1天起连续营养支持7d,各组等氮、等热卡。观察肠道形态学、肠道黏膜通透性、肠道细菌易位情况和血浆内毒素水平及肠道免疫功能检测。结果PN组肠黏膜明显萎缩,其绒毛高度、黏膜厚度、隐窝深度及绒毛表面积均显著低于其他各组(P<0.05);其肠黏膜通透性及内毒素值显著高于其他各组(P<0.05),细菌易位率(100%)明显高于其他各组(G-PN组60.0%,EN组33.3%,IEN组20.0%)。PN组CD4 T淋巴细胞和IgA 浆细胞分布显著低于其他各组(P<0.01)。结论EN在维护肠黏膜屏障功能、防止细菌及内毒素易位方面优于PN。免疫增强型EN在维护肠黏膜屏障、改善肠道免疫功能、防止细菌易位方面作用优于普通EN。     

缺血后处理对小肠缺血再灌注损伤的保护作用

目的：观察缺血后处理减轻肠缺血再灌注引起的小肠及远隔脏器损伤的效果,并探讨其机制。方法将家兔48只随机分为假手术组、缺血再灌注组、缺血后处理组,每组16只。再灌注2 h 后采集各组动脉血、静脉血及部分肠道组织、肝、肺组织,测动脉血中 TNF-α、IL-1β、IL-6、IL-10水平,测静脉血中 ALT、AST、BUN,Cr、LDH、CK-MB 活性,测内毒素水平,测定血清及小肠、肝、肺组织 MDA、MPO、CAT、SOD 水平,HE 染色,观察肠黏膜损伤情况,细菌培养观察细菌易位率。结果与缺血再灌注组比较,缺血后处理组血清及小肠、肝、肺组织中 MDA、MPO 水平明显降低, SOD、CAT 水平明显升高,静脉血 ALT、AST、LDH、CK-MB、BUN 下降;动脉血中 TNF-α、IL-1β、IL-6、内毒素降低,IL-10水平升高,肠黏膜损伤评分明显降低。结论缺血后处理可以减轻肠黏膜损伤,减少内毒素易位,促进抗炎因子的激活,抑制炎性介质的过度释放,提升小肠组织及远隔脏器的氧自由基的抗氧化能力,减轻小肠及远隔脏器组织损伤。     

肠道缺血再灌注损伤时肠淋巴干结扎对系统炎性反应的影响

目的比较大鼠肠道缺血再灌注损伤时肠淋巴干结扎与不结扎对循环中炎性介质和细菌内毒素的影响。方法采用肠道缺血再灌注模型进行肠系膜淋巴管结扎。大鼠随机分4组，每组10只：空白组（A组）；假手术组（B组）；肠道缺血再灌注组（C组）；肠道缺血再灌注加淋巴干结扎组（D组）。缺血再灌注后，作肠系膜淋巴结培养计算细菌易位率；检测循环中内毒素、D-乳酸、二胺氧化酶、TNF—α、IL-1β、IL-6和sICAM-1水平。结果细菌易位率A、B两组为0；C组40％，D组20％。与A、B组比较，C、D两组内毒素、D-乳酸和二胺氧化酶水平显著增高（P〈0．05），且D组显著低于C组；血循环中各细胞因子除sICAM-1在D组与C组之间没有显著差异外，C组的IL-1β、IL-6和TNF-α浓度均明显高于D组（P〈0．05）。结论肠道缺血再灌注损伤时，肠淋巴干结扎可减少细菌在肠系膜淋巴结的定植，并减轻肠道缺血再灌注的损伤及增加通透性，从而减轻全身炎性反应。     

谷氨酰胺强化肠外营养对大鼠小肠黏膜缺血再灌注损伤的影响

目的：构建大鼠小肠缺血再灌注模型,观察谷氨酰胺强化肠外营养对小肠黏膜屏障作用的影响,并探讨其作用机制。方法：30只雌性Wistar大鼠,随机分为正常对照组（N组）、传统肠外营养组（TPN组）和谷氨酰胺强化肠外营养组（TPN＋Gln组）3组,每组10只。TPN组和TPN＋Gln组构建小肠缺血再灌注模型后予完全肠外营养5d。观察3组小肠黏膜形态、血浆D-乳酸、内毒素、TNF-α、IL-6水平及小肠黏膜HO-1 mRNA和蛋白的表达。结果：TPN＋Gln组与TPN组相比,小肠黏膜组织形态明显改善,血浆D-乳酸、内毒素、TNF-α和IL-6水平均显著性降低,HO-1 mRNA及蛋白表达水平明显增高。结论：谷氨酰胺强化肠外营养可以明显减轻大鼠缺血再灌注小肠黏膜屏障损伤及炎性反应,保护黏膜屏障完整性,并促进HO-1 mRNA表达及HO-1合成。HO-1及其代谢产物的抗氧化、抗凋亡及抗炎作用可能是谷氨酰胺保护缺血再灌注损伤小肠的作用机制。     

肠腔灌注高氧液对缺血-再灌注后肠黏膜屏障损伤的保护作用

目的探讨缺血期经肠腔灌注高氧液对家兔肠缺血-再灌注后肠黏膜屏障损伤的保护作用。方法健康家兔24只,随机均分成三组:缺血-再灌注组(I/R组)、高氧液处理组(HOS组)、假手术对照组(Sham组)。Sham组只开腹游离但不夹闭肠系膜上动脉(SMA),另两组用无损伤动脉夹夹闭SMA1h。HOS组于缺血期以20ml.kg-1.h-1恒速向肠腔灌注高氧液1h,I/R组则以相同的方式灌注等量的生理盐水,松开动脉夹再灌注2h后取标本。光镜下观察各组肠黏膜组织形态学改变,测定肠黏膜组织ATP含量和肠道的氧摄取率(ERO2);定量分析门静脉血中细菌内毒素(ET)含量;检测血清中肿瘤坏死因子α(TNF-α)、乳酸(Lac)水平;观察细菌移位率。结果与Sham组相比,I/R组光镜下肠黏膜损伤严重,肠黏膜组织ATP含量及肠道的ERO2均明显下降,血液中ET含量、Lac和TNF-α水平明显升高(P<0.05或P<0.01),同时出现了广泛的细菌移位;经肠腔灌注高氧液(HOS组)能够明显改善小肠黏膜损伤及上皮细胞形态学改变,显著提高肠黏膜组织ATP含量及ERO2;明显降低血液中ET、Lac和TNF-α水平(P<0.05或P<0.01),同时显著减少肠道细菌移位率(P<0.05)。结论肠腔灌注高氧液能够显著减轻肠缺血-再灌注引起的小肠黏膜屏障功能障碍,是一种安全有效的小肠保护方法。     

人参皂甙Rb1在核因子NF-E2相关因子2/血红素氧合酶-1通路减轻肠缺血再灌注致急性肺损伤中的分子机制

目的 探讨人参皂甙Rb1对肠缺血/再灌注致急性肺损伤的保护效应及核因子NF-E2相关因子2(Nrf2)/血红素氧合酶-1(HO-1)通路参与该效应的分子机制.方法 成年雄性C57BL/6J小鼠随机分为5组:假手术组(S组);肠缺血/再灌注组(I/R组);再灌注+Rb1组(I/R +Rb1组);全反式维甲酸(ATRA)+再灌注组(ATRA+ I/R组);ATRA+再灌注+Rb1组(ATRA+ I/R+Rb1组).采用肠缺血/再灌注模型,Western blot检测肺组织Nrf2、HO-1表达变化;酶联免疫吸附试验(ELISA)法检测肺组织肿瘤坏死因子(TNF)-α、白细胞介素(IL)-6、IL-10水平;检测超氧化物歧化酶(SOD)活性及丙二醛(MDA)含量;检测肺湿/干比及肺组织病理损伤评分.结果 与S组比较,其他4组Nrf2、HO-1蛋白表达,TNF-α、IL-6、MDA含量,肺组织湿/干重比及肺组织病理评分增高(P＜0.05);与1/R组比较,1/R+ Rb1组Nrf2,HO-1蛋白表达,TNF-α,IL-6,MDA含量,肺组织湿/干重比及肺组织病理评分降低(P＜0.05);与I/R+ Rb1组比较,ATRA+ I/R组,ATRA+ I/R+ Rb1组Nrf2、HO-1蛋白表达,NF-α、IL-6、MDA含量,肺组织湿/干重比及肺组织病理评分增高(P＜0.05).SOD活性、IL-10水平与上述变化相反.结论 肠缺血/再灌注可引起急性肺损伤,人参皂甙Rb1后处理能通过激活Nrf2/HO-1通路减轻肠缺血/再灌注所致肺损伤.     

白细胞介素12在大鼠肺缺血再灌注损伤中的作用

目的 评价白细胞介素12(IL-12)在大鼠肺缺血再灌注损伤中的作用.方法 健康成年雄性SD大鼠24只,8-10周龄,体重250-280 g,采用随机数字表法,将大鼠随机分为3组(n=8):假手术组(S组),肺缺血再灌注损伤组([/R组),IL-12单克隆抗体组(IL-12组).S组只分离肺门不夹闭；I/R组夹闭肺门60 min后,恢复灌注2 h；IL-12组于夹闭肺门前1h尾静脉注射IL-12单克隆抗体200μg/kg.于再灌注结束时采集血样和肺绀织,测定血浆TNF-α浓度、辅助性T细胞(Th)1和Th2水平、肺组织湿干重(W/D)比、髓过氧化物酶(MPO)活性、MDA含量及动脉血氧分压(PaO2)及二氧化碳分压(PaCO2).光镜下观察肺组织病理学改变.结果 与S组比较,I/R组和IL-12组肺组织W/D比、MDA含量、MPO活性、血浆TNF-α浓度升高,I/R组PaO2降低,PaCO2、Th1水平和Th1/Th2升高(P＜0.01),Th2水平差异无统计学意义(P＞0.05),IL-12组PaO2、PaCO2、Th1、Th2水平及Th1/Th2差异无统计学意义(P＞0.05)；与I/R组比较,IL-12组PaCO2、肺组织W/D比、MDA含量、MPO活性、血浆TNF-α浓度、Th1水平和Th1/Th2降低,Th2水平和PaO2升高(P＜0.01).I/R组肺组织损伤明显,IL-12组肺组织损伤程度明显减轻.结论IL-12通过使Tn1/Th2失衡而参与肺缺血再灌注损伤.     

兴奋胆碱能通路对内毒素血症和肠缺血/再灌注动物肝脏功能的保护作用

目的:观察不同方式激活胆碱能受体途径对内毒素血症和肠缺血/再灌注动物肝脏功能的保护作用.方法:静脉注射内毒素(LPS,10 mg/kg和5 mg/kg)复制大鼠内毒素血症模型(每组10只),肠系膜上动脉夹闭1 h后松夹复制肠缺血/再灌注模型(每组6只),兔肠系膜上动脉部分阻断后4 h恢复血流复制兔肠部分缺血/再灌注模型(每组5只).内毒素血症大鼠分别施与迷走神经刺激或电针副交感神经相关穴位(后三里穴),并分别设模型组、假手术组和迷走神经切断组或电针假穴组;肠缺血/再灌注动物经肠袋(距离回盲部15 cm处起始,向空肠端作一个长约10 cm肠袋,保留血液供应)给予卡巴胆碱(大鼠:0.1 mg/kg;兔:3μg/kg),并设假手术组和模型组.各组大鼠于实验结束时、各组兔于上动脉阻断0、2、4、6、8 h及1、2、3 d取股动脉血测定血浆丙氨酸转氨酶(ALT)活性.结果:与模型组、迷走神经切断组或电针假穴组比较,采用迷走神经刺激或电针刺激副交感神经相关穴位(后三里穴)明显降低内毒素血症大鼠早期血浆ALT活性(P＜0.05或P＜0.01);肠缺血及再灌注后大鼠ALT明显升高,肠袋给予卡巴胆碱后ALT水平均有明显改善.肠袋输注卡巴胆碱兔血浆ALT活性在缺血/再灌注早期较缺血前增加,再灌注后逐渐恢复,伤后3 d基本接近正常水平,而模型组则逐渐升高.结论:通过刺激副交感神经或局部给予拟胆碱药的方式激活胆碱能受体途径对内毒素血症和肠缺血/再灌注动物肝脏功能具有不同程度的保护作用.     

乌司他丁对肝脏肿瘤切除术患者肝脏缺血-再灌注损伤的保护作用

目的观察乌司他丁对肝脏肿瘤切除术患者肝脏缺血-再灌注损伤的保护作用。方法选择32例ASAⅠ～Ⅲ级拟行肝脏肿瘤切除术的患者,随机均分为乌司他丁组(U组)和对照组(C组)。U组:乌司他丁12000U/kg加在生理盐水50ml中,麻醉诱导后切皮前经颈内静脉泵入;C组:注入等量的生理盐水。在切皮时(T1)、缺血后10min(T2)、再灌注10min(T3)、30min(T4)、1h(T5)、术后1d(T6)、2d(T7)抽取静脉血测定血浆中谷草转氨酶(AST)、谷丙转氨酶(ALT)、超氧化物歧化酶(SOD)活性,丙二醛(MDA)水平、白细胞介素1β(IL-1β)、白细胞介素6(IL-6)、肿瘤坏死因子(TNF-α)浓度。结果与T1时比较,T3～T6时两组的AST、ALT活性、MDA水平、IL-1β、IL-6、TNF-α浓度均明显升高;SOD活性明显降低(P<0.05)。与C组比较,T2～T7时U组的AST和ALT活性明显降低;T3～T5时MDA水平、IL-1β、IL-6和TNF-α浓度均明显降低;T3～T5时SOD活性明显升高(P<0.05)。结论乌司他丁能抑制氧自由基生成和炎症因子的释放,对肝脏缺血-再灌注损伤具有保护作用。     

缺血后适应在兔急性肠系膜缺血再灌注损伤模型中的作用

目的 观察缺血后适应干预措施能否减轻兔急性肠系膜缺血再灌注损伤.方法 将雄性新西兰兔120只随机分为空白对照(Con)组(仅开腹显露SMA)、缺血再灌注(I/R)组[肠系上动脉(superior mesenteric artery,SMA)缺血30 min后持续灌注120 min]、缺血后适应1(IpostC1)组(SMA缺血30 min后行3个循环的灌注30 s/阻断30 s,再持续灌注117 min)、缺血后适应2(IpostC2)组(SMA缺血30 min后行3个循环的灌注60s/阻断60 s,再持续灌注114 min),每组30只.干预后采集各组兔处理后下腔静脉血及部分肠道组织标本,试剂盒测定血清及肠道组织内丙二醛(MDA)、髓过氧化酶(MPO)水平,HE染色,Chiu 6级评分法观察肠黏膜损伤情况. 结果 与对照组比较,I/R组及IpostC1组、IpostC2组血清及肠道组织中MDA、MPO水平明显增加(P＜0.01),肠黏膜损伤评分明显升高(P＜0.01).与I/R组相比,IpostC1组血清和肠道组织中MDA、MPO水平及肠黏膜损伤评分明显降低(P＜0.01),而IpostC2组血清和肠道组织中MDA、MPO水平及肠黏膜损伤评分无明显降低(P＞0.05).结论 缺血后适应可明显降低兔急性肠系膜缺血再灌注损伤后下腔静脉血和肠道组织中MDA、MPO水平及肠黏膜损伤.     

Protective effects of glucagon-like peptide 2 on intestinal ischemia-reperfusion rats

Our objective was to evaluate the protective effects of glucagon-like peptide 2 (GLP-2) on intestinal ischemia/reperfusion (I/R) rats. Thirty-two rats were randomly assigned to four experimental groups, each of 8: Group A, sham rats underwent laparotomy only, without superior mesenteric artery (SMA) occlusion; Group B, I/R animals underwent laparotomy and occlusion of the SMA for 60 minutes followed by 120 minutes of reperfusion; Group C, I/R animals underwent intestinal I/R, and received pretreatment with GLP-2 for 3 days preoperatively; and Group D, I/R animals underwent intestinal I/R, received pretreatment with GLP-2 as above, and during the reperfusion phase were injected intravenously with GLP-2. After the reperfusion of intestinal ischemia, samples of intestinal mucosa, mesenteric lymph nodes (MLN) and blood were prepared for determination. In the pretreatment rats with GLP-2 (group C), Chiu's scores, bacterial colony counts, serum D-lactate, intestinal mucosal MDA and ET-1, and serum endotoxin, TNF-alpha and IL-6 were significantly reduced compared with intestinal I/R rats (group B). Administration of GLP-2 during the reperfusion phase following pretreatment (group D) showed further protective effects in comparison with the pretreatment rats (group C). We conclude that treatment with GLP-2 attenuates intestinal I/R injury, reduces bacterial translocation, inhibits the release of oxygen free radicals and ET-1, and may well inhibit the production of proinflammatory cytokines.     

GLP-2alpha accelerates recovery of mucosal absorptive function after intestinal ischemia/reperfusion

BACKGROUND/PURPOSE: The authors' previous laboratory results have shown that rats treated for 3 days with intravenous GLP-2alpha, a synthetic protease-resistant form of glucagonlike peptide-2, showed increased mucosal mass and absorptive function when compared with saline-treated controls after intestinal ischemia/reperfusion (I/R). This study was designed to explore the temporal relationship between injury that occurs secondary to intestinal I/R and recovery of mucosal absorptive function with and without GLP-2alpha treatment. METHODS: Each of 18 male Sprague-Dawley rats (300 to 333 g) was subjected to superior mesenteric artery occlusion for 30 minutes, during which time a jugular venous catheter was placed and connected to a subcutaneous infusion pump. Rats were divided into 4 groups based on the type and duration of infusion as follows: group 1, systemic saline at 1 microL/h for 24 hours (n = 5); group 2, systemic GLP-2alpha at 100 microg/kg/d for 24 hours (n = 5); group 3, systemic saline at 1 microL/h for 72 hours (n = 4); and group 4, systemic GLP-2alpha at 100 microg/kg/d for 72 hours (n = 4). Immediately after the infusions, (14)C-galactose and (14)C-glycine absorption was measured using an in vivo, closed-recirculation technique and expressed as micromoles per square centimeter intestine +/- SEM. Statistical analysis was performed using analysis of variance. RESULTS: Twenty-four hours after intestinal I/R injury, there was a decrease in substrate absorption but no significant difference between the saline and GLP-2alpha-treated groups (galactose absorption, 1.13 +/- 0.09 in group 1 v 1.35 +/- 0.11 in group 2, P =.15; glycine absorption, 1.18 +/- 0.13 in group 1 v 1.34 +/- 0.15 in group 2, P =.36). However, after the 72-hour infusion, absorption of galactose and glycine was significantly increased in the rats receiving GLP-2alpha as compared with the saline-infused control group (galactose absorption, 1.24 +/- 0.13 in group 3 v 1.88 +/- 0.10 in group 4, P <.01; glycine absorption, 1.64 +/- 0.07 in group 3 v 2.05 +/- 0.08 in group 4, P <.05). Compared with previously determined levels of absorption in normal, uninjured rat intestine (1.50 +/- 0.12 micromol/cm(2) for galactose and 1.85 +/- 0.17 micromol/cm(2) for glycine), after I/R a 72-hour infusion of GLP-2alpha increased galactose absorption 26% (P <.05) and glycine absorption 11% (P =.29) beyond baseline. CONCLUSIONS: When initiated at the time of intestinal I/R, a continuous infusion of GLP-2alpha accelerated recovery of mucosal absorptive function in rats. Remarkably, carbohydrate absorption at 72 hours was increased to a level significantly greater than that in normal, uninjured rat intestine. J Pediatr Surg 36:570-572.     

Glucagonlike peptide-2 analogue enhances intestinal mucosal mass after ischemia and reperfusion

BACKGROUND/PURPOSE: Glucagonlike peptide-2 (GLP-2), a product of the posttranslational processing of proglucagon, has been shown to enhance mucosal mass and function in both normal intestine and in the residual intestine after massive small bowel resection. This study was designed to determine if a synthetic, protease-resistant analogue of GLP-2 (GLP-2alpha) can enhance mucosal mass in small intestine after ischemia and reperfusion (I/R) injury. METHODS: Ten young adult male Sprague-Dawley rats underwent laparotomy and superior mesenteric artery occlusion for a period of 40 minutes. During this period of ischemia, each rat underwent placement of a jugular venous catheter that was connected to a subcutaneously placed osmotic pump designed to deliver its contents over 3 days. The rats were divided into 2 groups based on the contents of the pumps: group 1, saline at 1 microL/h (n = 6) and group 2, GLP-2alpha at 100 microg/kg/d (n = 4). Three days after insertion of the pumps the small intestine was harvested from the surviving rats for determination of mucosal DNA and protein content. Statistical analysis was performed using unpaired Student's t test. RESULTS: After I/R injury to the small intestine, a 3-day systemic infusion of GLP-2alpha significantly increased mucosal DNA content 41% (P<.05) and mucosal protein content 60% (P<.05) when compared with saline-treated controls. In addition, infusion of GLP-2alpha reduced mortality from 50% to 25%. CONCLUSIONS: These data show for the first time that GLP-2alpha enhances mucosal mass following I/R injury to the small intestine. GLP-2alpha may be of benefit to patients with intestinal ischemia syndromes such as necrotizing enterocolitis and midgut volvulus.     

胰高血糖素样肽-2对实验性梗阻性黄疸大鼠肠道屏障功能的保护作用

目的 探讨胰高血糖素样肽-2(GLP-2)对梗阻性黄疸模型大鼠肠道屏障功能的保护作用机制.方法 将72只SD大鼠随机分为3组:实验组(T组,n=24)、手术对照组(C组,n=24)和假手术组(SO组,n=24).T组和C组双重结扎胆总管,建立梗阻性黄疸模型;SO组开腹但不结扎胆总管.结扎后,T组腹腔注射GLP-2 (250 μg·kg-1·d-1),C组和SO组注射等体积0.01 mol/L的PBS溶液.于手术后第1、3、7天分别分批处死动物.应用RT-PCR技术半定量检测空肠黏膜GLP-2R mRNA的表达,应用免疫组织化学方法检测肠黏膜B细胞淋巴瘤/白血病基因-2(bcl-2)的表达.结果 T组肠黏膜GLP-2R mRNA的表达量比C组高,差异有统计学意义(P＜0.05),比SO组表达量稍低,差异无统计学意义(P＞0.05);C组肠黏膜bcl-2的表达于术后逐渐减少,差异有统计学意义(P＜0.05),且其表达量较SO组和T组少(P＜0.05),特别是第3、7天时,比SO组和T组降低更明显(P＜0.05).结论 GLP-2可以增加实验性梗阻性黄疸时肠黏膜细胞GLP-2R的表达,阻止肠黏膜细胞的凋亡,从而发挥保护肠道屏障功能的作用.     

Heat-shock protein-73 protects against small intestinal warm ischemia-reperfusion injury in the rat

BACKGROUND: The protective effects of heat-shock protein (hsp) in rat small intestinal warm ischemia-reperfusion (I/R) injury are poorly understood. METHODS: Hsp-73 expression was induced in rat small intestine with use of sodium arsenite injected (6 mg/kg) through a catheter cannulated into the left common carotid artery 24 hours before ischemia (group 1). In the control group an equal volume of phosphate-buffered saline solution was injected (group 2). To block the induction of hsp-73 expression, sodium arsenate and quercetin (5 mg/kg) were injected (group 3). RESULTS: The mean peak plasma levels of tumor necrosis factor-alpha and cytokine-induced neutrophil chemoattractant after reperfusion were lower in group 1 than in group 2. The tissue myeloperoxidase activity after reperfusion was lower in group 1 than in group 2. The mean peak plasma level of interleukin-10 after reperfusion was higher in group 1 than in group 2. The induction of hsp-73 expression reduced the synthesis of nitric oxide and the magnitude of the small intestinal warm I/R injury. The results in group 3 were similar to those in group 2. CONCLUSION: Hsp-73 protects against small intestinal warm I/R injury by inhibiting the synthesis of inflammatory cytokines and the activation of neutrophils and by accelerating the synthesis of anti-inflammatory cytokines.     

血必净联合维拉帕米对大鼠小肠缺血再灌注损伤的实验研究

目的探讨血必净联合维拉帕米对大鼠小肠缺血再灌注（I／R）损伤的保护作用及其可能机制。方法制作小肠缺血再灌注模型,SD大鼠50只随机分为假手术组（A组）、缺血再灌注组（B组）、血必净组（c组）、维拉帕米组（D组）及血必净和维拉帕米联合治疗组（E组）,各10只。分别检测各组大鼠小肠缺血45min再灌注0h、2h时血清中肿瘤坏死因子α（TNF—α）、白细胞介素1β（IL-1β）、丙二醛（MDA）的含量;同时观察小肠黏膜组织病理学变化。结果缺血再灌注组小肠组织病理学改变较其他组明显;在再灌注0h、2h时B、C、D、E组血清中TNF—α、IL-1β、MDA含量均较A组显著升高（P〈0．05）;再灌注2h时C、D、E组血清中TNF—α、IL-1β、MDA含量均较B组明显降低（P〈0．05）,但C、D两组间差异无统计学意义;C、D组血清中TNF—α、IL-1β、MDA含量均较E组明显升高（P〈0．05）。结论血必净、维拉帕米能减轻大鼠小肠缺血再灌注损伤,二者联合用药有协同保护作用,效果更明昴。     

Parenteral nutrition impairs gut-associated lymphoid tissue and mucosal immunity by reducing lymphotoxin Beta receptor expression

OBJECTIVE: To determine the effects of parenteral nutrition (PN) on LTbetaR in gut-associated lymphoid tissue (GALT), particularly the intestine and Peyer's patches (PP). SUMMARY BACKGROUND DATA: Lack of enteral stimulation with PN impairs mucosal immunity and reduces IgA levels through depression of GALT cytokines (IL-4 and IL-10) and GALT specific adhesion molecules. We have shown that each is critical to intact mucosal immunity through effects on lymphocyte homing, IgA production, and resistance to antibacterial and antiviral immunity. IgA is the principal specific immunologic mucosal defense. LTbetaR stimulation controls production of IL-4, the adhesion molecule MAdCAM-1, and other key components of GALT, all of which are important in increasing IgA levels and maintaining mucosal defenses. METHODS: Experiment 1: LTbetaR expression in intestine and PP was analyzed by Western blot after 5 days of chow, a complex enteral diet (CED), or PN. Diets were isocaloric and isonitrogenous except for chow. Experiment 2: After completing pilot experiments to determine the appropriate dose of the LTbetaR agonistic antibody, mice received chow, PN + 5 mug of anti-LTbetaR mAb (2 times/d, i.v.) or PN + isotype control antibody. PP lymphocytes and intestinal IgA levels were measured after 2 days. RESULTS: Lack of enteral stimulation with PN significantly decreased LTbetaR expression in intestine and PP compared with chow and CED. LTbetaR stimulation with an agonistic anti-LTbetaR mAb significantly increased PP lymphocyte counts and intestinal IgA in PN fed-mice. CONCLUSIONS: LTbetaR expression is critical for GALT control mechanisms and intact mucosal immunity. PN reduces LTbetaR expression, PP lymphocytes, and intestinal IgA production. Exogenous LTbetaR stimulation reverses PN-induced depression of gut mucosal immunity.     

加味玉屏风散与流感疫苗预防流感的黏膜免疫效应与机制研究

目的：研究维生素C（Vit C）玉屏风散合剂和流感疫苗预防流感的免疫效应和机制,探索中西医结合预防流行性感冒的优化方案。方法选取BALB/c小鼠36只,随机分为对照组、Vit C玉屏风散组和流感疫苗组,分别给予Vit C玉屏风散合剂连续灌胃14 d,流感病毒亚单位疫苗肌肉注射免疫小鼠,而对照组不做任何处理,模仿人体生理状态;上述动物连续喂养14 d后取血清、支气管肺泡灌洗液（BALF）和肠灌洗液;ELISA法检测肺肠灌洗液中SIgA和IgG的含量,以及外周血Th1细胞因子（IL-2、IFN-γ和TNF-α）和Th2细胞因子（IL-4、IL-6和TGF-β）含量。结果 VitC玉屏风散上调支气管肺泡灌洗液SIgA和IgG水平（SIgA：t =1.68,P ＞0.05;IgG：t =-0.85,P ＞0.05）,对血液Th1和Th2细胞因子水平无显著影响（t 分别为0.51、0.58、1.55、1.51、0.72和1.21;P均＞0.05）,细胞因子呈Th1优势反应（Th1/Th2=1.19）;流感疫苗上调血液中和IgG抗体水平（Z =0.20,P ＞0.05）,上调血液IFN-γ、TNF-α、IL-6和TGF-β水平（t 分别为1.78、0.95、2.05和0.71;P均＞0.05）可显著提高血液IL-2和IL-4水平（t分别为2.53和2.29;P均＜0.05）,且Th1漂移更加明显（Th1/Th2=1.35）。结论 VitC玉屏风散可直接激活黏膜免疫防御机制,促进呼吸道保护性抗体SIgA和IgG的形成,抵御病毒入侵;流感疫苗主要激活系统免疫,上调系统免疫水平,对入侵体内的流感病毒发挥细胞免疫和体液免疫作用。二者可以优势互补,通过不同的机制在防治流行性感冒的不同阶段发挥作用。     

Disruption of P-selectin signaling modulates cell trafficking and results in improved outcomes after mouse warm intestinal ischemia and reperfusion injury

BACKGROUND: This study analyzes the role of T lymphocytes and neutrophils (PMN) in intestinal ischemia and reperfusion injury (IRI) using either P-selectin blockade or elimination. METHODS: Using a model of severe mouse warm intestinal IRI, the following groups were performed: group 1: wild type C57BL6 no treatment; group 2: wild type treated with r-PSGL1-Ig; group 3: C57BL6 genetically deficient in P-selectin. Survival was assessed at day 7; intestine was assayed for histopathology, apoptosis, myeloperoxidase (MPO), inflammatory cytokines, hemoxygenase-1 (HO-1), and CD3 lymphocytes. Standard statistical comparison was undertaken. RESULTS: The survival was significantly (P < 0.01) improved in the treatment groups: group 1, 50%; group 2, 90%; group 3, 100%. Graded histopathology and crypt apoptosis were improved in groups 2 and 3. MPO and CD3 positive cells were significantly reduced in groups 2 and 3. A significant reduction in inflammatory/Th1-type cytokines was seen in groups 2 and 3 as compared to group 1. Conversely, a significant increase in Th2-type cytokines and HO-1 production was seen selectively in groups 2 and 3. CONCLUSIONS: This study demonstrates the importance of P-selectin signaling in warm, murine intestinal IRI in that either the blockade of or the genetic deficiency in P-selectin confers a survival advantage and reduction in tissue injury/inflammation. The mechanism involves a reduction of PMN and CD3 T cell infiltration and an alteration in the cytokine microenvironment in favor of a Th2 profile. These data implicate T lymphocyte as an important regulatory cell in this inflammatory process.