MicroRNA-1和microRNA-21在缺血预处理、后处理及远端预处理中的表达变化

目的 通过离体缺血-再灌注心脏模型,观察缺血预处理(IPC)、缺血后处理(IPO)和肢体远端预处理(RIPC)后心脏microRNA1(miRNA-1)和microRNA21 (miRNA-21)的表达变化,以及它们所调控靶蛋白热休克蛋白70 (HSP70)和程序性细胞死亡4(PDCD4)表达变化,期望从miRNA调控水平揭示心脏的内源性保护机制.方法 取Sprague-Dawley (SD)大鼠心脏,建立离体Langendorff心肌缺血-再灌注模型,随机分为4组(每组12只),对照组、IPC组、IPO组和RIPC组.检测各组血流动力学指标,蛋白印迹法(Western blotting)检测PpDCD4、HSP70、B细胞淋巴瘤/白血病-2(Bc1-2)和Bc1-2相关X蛋白(Bax)含量,taqman探针法检测miRNA-1和miRNA-21含量,末端脱氧核苷酸转移酶介导的原位缺口标记法(TUNEL)检测心肌细胞凋亡,2,3,5-氯化三苯基四氮唑(TTC)法检测心肌梗死面积. 结果 IPC组心肌的miRNA-1和miRNA-21表达明显高于对照组,但RIPC组和IPO组心肌的miRNA-1表达较对照组明显降低( P＜0.05).IPC组、RIPC组和IPO组心肌中HSP70、PDCD4和Bax蛋白含量较对照组明显减少(P＜ 0.05),Bc1-2蛋白含量各组间差异无统计学意义.IPC组、RIPC组和IPO组左室心肌梗死面积/左室总面积以及心肌细胞凋亡率明显低于对照组(P＜ 0.05). 结论 miRNA-1和miRNA-21在缺血预处理、缺血后处理和远端预处理后,表达变化是不同的,同时各处理组中miRNA与其靶蛋白并不都是负性调节关系.     

Apoptosis of sinusoidal endothelial cells occurs during liver preservation injury by a caspase-dependent mechanism.

BACKGROUND: Cold ischemia/warm reperfusion (CI/WR) liver injury remains a problem in liver transplants. Sinusoidal endothelial cells (SEC) are a target of CI/WR injury, during which they undergo apoptosis. Because caspase proteases have been implicated in apoptosis, our aim was to determine whether liver CI/WR injury induces a caspase-dependent apoptosis of SEC. METHODS: Rat livers were stored in the University of Wisconsin (UW) solution for 24 hr at 4 degrees C and reperfused for 1 hr at 37 degrees C in vitro. Apoptosis was quantitated using the TUNEL assay, and caspase 3 activation determined by immunohistochemical analysis. Rat liver orthotopic liver transplants (OLT) were also performed using livers stored for 30 hr. RESULTS: Terminal deoxynucleotide transferase-mediated dUTP nick end labeling (TUNEL) positive hepatocytes were rare and did not increase during CI/WR injury. In contrast, TUNEL positive SEC increased 6-fold after reperfusion of livers stored under cold ischemic conditions, compared with controls or livers stored but not reperfused. Immunohistochemical analysis demonstrated active caspase 3 only in endothelial cells after CI/WR injury. When IDN-1965, a caspase inhibitor, was given i.v. to the donor animal and added to UW solution and the reperfusion media, TUNEL positive endothelial cells were reduced 63+/-11% (P<0.05). Similarly, the duration of survival after OLT was significantly increased in the presence of the inhibitor. CONCLUSION: During liver CI/WR injury: 1) selective apoptosis of endothelial cells occurs; 2) caspase 3 is activated only in endothelial cells; and 3) a caspase inhibitor reduces endothelial cell apoptosis and prolongs animal survival after OLT. The pharmacologic use of caspase inhibitors could prove useful in clinical transplantation.     

Pyruvate inhibits hepatic ischemia-reperfusion injury in rats

BACKGROUND: Ischemia/reperfusion (I/R) injury is a limiting factor in liver transplantation. We have recently shown that pyruvate (PY) inhibits intestinal and renal I/R injury. This study aims to evaluate the protective effect of PY on hepatic I/R injury. METHODS: ACI rats were treated with PY, whereas control animals received placebo. Rats were killed after 60 min of partial hepatic ischemia and after 2, 6, 24, and 48 hr of reperfusion. For each time point, serum aspartate aminotransferase, alanine aminotransferase, and lactate dehydrogenase were measured, and liver biopsy specimens were obtained to evaluate morphology, DNA fragmentation, and apoptosis (terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick end labeling). RESULTS: The survival rate 48 hr after I/R was 83% in the control group, and 100% in the PY-treated group (P>0.05). Increased enzymatic levels and histologic findings showed increased liver damage in the untreated group compared with PY. In control rats, apoptosis was enhanced after 1 hr of ischemia and peaked after 2 hr of reperfusion, to decrease gradually 48 hr after reperfusion; in the PY group apoptosis was delayed and reduced. After 1 hr of ischemia, the number of apoptotic nuclei was significantly increased in control livers compared with normal preischemic livers, whereas the number was significantly reduced by PY. After 2 hr of reperfusion, the maximum number of apoptotic cells was observed, whereas PY significantly reduced the amount of apoptotic cells (P<0.05). Apoptosis was delayed in PY-treated livers to 6 hr after reperfusion, peaking at a significantly lower count compared with placebo-treated controls (P<0.05). CONCLUSION: These data indicate that PY has a protective effect on I/R injury of the liver.     

Prostaglandin E1 improves survival rate after 95% hepatectomy in rats

BACKGROUND/AIM: Prostaglandin E1 (PGE1) has a wide-ranging effect on cytoprotection. Overproduction of heat shock protein 70 (HSP70) in the liver protects hepatocytes under various pathologic conditions. In this study, we examined the effect of a nontoxic HSP-inducer, PGE1, on acute liver failure after 95% hepatectomy in rats. METHODS: PGE1 or vehicle was intravenously administered to rats 30 min before and during hepatectomy. RESULTS: Nine of 30 rats pretreated with PGE1 survived, whereas all 20 rats pretreated with vehicle died within 96 h after operation. During the 24-h postoperative period, PGE1 significantly suppressed the release of alanine aminotransferase and elevation of hyaluronic acid. Histological examination showed that the vacuolized hepatocytes and round hepatocytes with pyknotic nuclei are frequently seen in rats pretreated with vehicle, whereas active regeneration is seen in rats pretreated with PGE1. During the first 24 h after surgery, HSP70 induction was absent in the residual livers of vehicle-treated rats. In contrast, PGE1 stimulated the HSP accumulation within 24 h, and viable hepatocytes contained abundant HSP70 in their nuclei. CONCLUSION: Our results suggest that PGE1 may prevent acute liver failure after massive hepatectomy, at least in part, by enhancing HSP70 production in the residual liver.     

Histopathological features of liver damage induced by laser ablation in rabbits

BACKGROUND AND OBJECTIVE: Possible mechanisms that promote or interfere with the effects of laser ablation of the liver have not been clarified. The aim of this study was to define the chronological alterations in the normal rabbit liver at early stages after laser ablation. STUDY DESIGN/MATERIALS AND METHODS: Rabbit livers were ablated with a laser via an optical fiber and then analyzed histopathologically by immunostaining for heat shock protein 70 (HSP70) and by the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labeling (TUNEL) method. RESULTS: The lesions increased in size progressively over the 24 h that followed ablation and the area of the lesion coincided with the area that had been heated above 43 degrees C. TUNEL-positive hepatocytes were surrounded, at some distance, by HSP70-positive hepatocytes were surrounded, at some distance, by HSP70-positive hepatocytes at 6 h, and such cells were in contact with each other at 24 h. CONCLUSIONS: Injury to hepatocytes induced by laser ablation increases for 24 h and dying cells express nuclear HSP70, with subsequent fragmentation of DNA.     

Feasibility of new heating method of hepatic parenchyma using a sintered MgFe2O4 needle under an alternating magnetic field

BACKGROUND: Magnetic metal particles such as magnesium ferrite (MgFe2O4) induce heat energy under an alternating magnetic field that was produced by electric current. We have developed a new heating device using a sintered MgFe2O4 needle under an alternating magnetic field. This device can repeatedly heat target tissue at lower temperatures than that for radiofrequency ablation therapy. This study aims to assess whether the new heating device has the ability to heat rat liver tissue. METHOD: A small needle made from MgFe2O4 particles was prepared by sintering at 1100 degrees C and inserted into rat liver tissue. The rat liver was then heated under an alternating magnetic field, 4 kA/m, for 30 min. We measured the temperature of rat tissue during the heat treatment, and sequentially evaluated histological changes and hepatocyte cellular activity after heat stimulus by using nicotinamide adenine dinucleotide diaphorase staining and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling staining. RESULTS: The mean temperature of the liver tissue during heating was 60.7 +/- 1.1 degrees C. Immediately after heating, nuclei of the hepatocytes were hyper-chromatin, with hepatocytes negative for nicotinamide adenine dinucleotide diaphorase activity in the heat-injury area. The injury area spread progressively until 3 d after heating, when the area was surrounded by fibroblasts, with hepatocytes positive for terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling staining. CONCLUSIONS: This is the first time that a ferromagnetic metal heating device under an alternating magnetic field has achieved a temperature beyond 60 degrees C and led hepatocytes to complete cell death. This device would be of future use as a local heat-treatment for human liver cancer.     

Calpain inhibition prevents sinusoidal endothelial cell apoptosis in the cold ischemic rat liver.

BACKGROUND: Cold preservation of the liver followed by reperfusion results in sinusoidal endothelial cell (SEC) apoptosis. Calpain-like activity is dramatically increased during reperfusion and inhibition of calpains results in lower graft injury and longer survival. Recently, calpains have been implicated in inducing apoptosis. Our aim was to determine the effect of calpain inhibition on SEC apoptosis. METHODS: Livers were stored in the University of Wisconsin solution for 24 hr (survival conditions) and 40 hr (nonsurvival conditions) and ex vivo reperfused for 1 hr at 37 degrees C. Calpain-like activity was inhibited in some experiments using an i.p. injection of a selective inhibitor 2 hr before explantation. Apoptosis was quantified using the terminal deoxynucleotidyl trans. ferase-mediated dUTP nick end-labeling assay. Cross-inhibition by the inhibitor was determined for caspases 1 and 3. RESULTS: Apoptosis of exclusively the SEC was a key feature of reperfusion injury after both storage periods in University of Wisconsin solution after 1 hr normothermic reperfusion. Inhibition of calpain activity with Cbz-Val-Phe methyl ester resulted in a 50% reduction of apoptotic SEC in the 40-hr preserved liver, and an almost complete abrogation of SEC apoptosis after 24 hr preservation. Only minimal cross-inhibition of caspases was determined at high concentrations in vitro by the calpain inhibitor. CONCLUSION: Apoptosis of exclusively SEC is a key feature of reperfusion injury partially mediated through calpain-dependent processes. Calpain inhibition reduces the number of apoptotic SEC. Based on these data and our previous work, calpain inhibition may prove to be useful in clinical transplantation.     

他克莫司对大鼠急性脊髓损伤后细胞凋亡及热休克蛋白70表达的影响

目的探讨脊髓损伤后他克莫司（FK506）对热休克蛋白70表达的影响及其与神经细胞凋亡的关系。方法采用Allen法建立大鼠急性脊髓损伤模型。雄性Wistar大鼠72只,随机分为假手术组（n=12）、损伤组（n=30）和FK506组（n=30）。FK506组伤后5min一次性经尾静脉注射FK506（0．3mg／kg）,假手术组和损伤组以相同方法给予0．9％的生理盐水。术后行脊髓功能评分;逆转录聚合酶链反应（RT—PCR）检测热休克蛋白70mRNA的表达;免疫组织化学染色检测半胱氨酸天冬氨酸蛋白酶-3和热休克蛋白70的表达;原位末端标记法（TUNEL）检测神经细胞凋亡。结果热休克蛋白70mRNA和蛋白的表达在FK506组较损伤组明显增加（P〈0．05）,分别于伤后6、24h达高峰;FK506组半胱氨酸天冬氨酸蛋白酶-3的表达和神经细胞凋亡均较损伤组明显减少（P〈0．01,P〈0．05）;脊髓功能评分在FK506组显著优于损伤组（P〈0．05）。结论FK506能抑制脊髓损伤后半胱氨酸天冬氨酸蛋白酶-3的活性,减轻神经细胞凋亡,促进脊髓功能恢复,其机制可能与诱导热休克蛋白70表达增加有关。     

The influence of brain death on liver in rats

OBJECTIVE: Donor brain death produces functional and morphological changes in peripheral organs. We examined the influence of brain death on liver function. METHODS: Fifty rats were randomly divided into three groups: controls (C), sham-operated (E1), and brain-dead (E2). All rats underwent tracheotomy with assisted respiration. The sera of rats at 1 and 3 hours after brain death were tested for the levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), hyaluronic acid (HA), and endothelin-1 (ET-1). At the end of assisted respiration, liver samples were collected for ultrastructural observation. RESULTS: At 1 and 3 hours, the levels of ALT, AST, HA, and ET-1 in group E2 were significantly higher than those in groups C and E1 (P < .05). The levels of ALT, AST, HA, and ET1 at 3 hours were significantly higher than those at 1 hour (P < .05). Under the electronic microscope, Kupffer cells were activated, sinusoidal endothelial cells (SEC) denuded, fenestration widened, and hepatocytes under the SEC exposed in group E2. In group C and E1, Kupffer cells were not obviously activated and SEC were almost intact. CONCLUSIONS: Brain death damages hepatocytes and nonparenchymal cells in rat. Endothelin-1 and Kupffer cells play an important role in the process. The clearance of hyaluronic acid may provide reliable index to judge SEC function after brain death.     

Protection by vascular endothelial growth factor against sinusoidal endothelial damage and apoptosis induced by cold preservation

BACKGROUND: It is well known that sinusoidal endothelial cell (SEC) damage during cold preservation of liver tissue is closely involved in early graft failure. The objective of this study was to investigate the involvement of apoptosis in the SEC damage induced by cold preservation and to demonstrate the protective effect of vascular endothelial growth factor (VEGF) on SEC injury, including apoptotic changes. METHODS: Isolated SECs and liver tissue of Wistar rats were cold-preserved in University of Wisconsin (UW) solution, and the protective effect of VEGF was then investigated. Isolated SECs were cultured for 24 hr, and divided into the following 3 groups: Group A, in which the cells were cultured for an additional 27 hr, Group B, in which the cells were cold-preserved in UW solution for 3 hr, and then recultured for 24 hr, and Group C, in which 20 ng/ml of VEGF was added to both the culture medium and the UW solution of cells cultured according to the Group B protocol. Each group of SECs was morphologically examined using the phase contrast microscopic method and the transmission electron microscopic method (TEM), and quantitatively analyzed using the WST-1 assay. Rat livers were cold-preserved in UW solution and divided into the VEGF(+) group and the VEGF(-) group, depending on whether VEGF was added or not. Each group of livers were analyzed by scanning electron microscopic method (SEM) after 24 hr of preservation. The hyaluronic acid uptake rate (HUR) was also determined after 6 hr of preservation. After 24 hr of preservation and 6 hr of reperfusion, tissues were examined by TEM and by the terminal deoxynucleotidyl transferase d-uridine triphosphate nick end labeling (TUNEL) assay. RESULTS: The phase contrast microscopic method and the WST-1 assay showed a protective effect of VEGF against the injury to isolated SECs during cold preservation and subsequent reculturing. Apoptosis was detected immediately by TEM after isolation of SECs, and the number of apoptotic cells increased with the incubation time. This increase was accelerated after cold preservation. The scanning electron microscopic method and the hyaluronic acid uptake rate showed a protective effect of VEGF against SEC damage in the cold-preserved livers. In the liver tissue, the TEM and the TUNEL assay detected apoptosis of SECs only after cold preservation and subsequent reperfusion. VEGF suppressed the apoptosis of SECs induced by cold preservation in both isolated cells and liver tissue. CONCLUSIONS: We demonstrated that SEC damage in the cold preservation of liver tissue was caused mainly by apoptosis, which required subsequent reperfusion. Moreover, isolated SECs showed spontaneous occurrence of apoptotic changes during culture, and these changes were accelerated by the preceding cold preservation. This is the first report to demonstrate the apoptotic changes of SECs seen here were inhibited by VEGF.     

Induction of Heat Shock Response: Effect on the Rat Liver with Carbon Tetrachloride-induced Fibrosis from Ischemia-reperfusion Injury

n = 56) received no pretreatment except anesthesia, and the heat shock group (group HS, n = 56) were exposed to heat shock (42°C) for 15 minutes. After a 48-hour recovery all rats were subjected to 30 minutes of warm ischemia. Western blotting analysis was employed for heat shock protein (HSP) 72 detection. The adenine nucleotide levels in liver tissue and the liver enzyme levels in serum were measured before and after ischemic intervention (seven animals were used at each of six time point measurements in both groups). HSP72 was induced in group HS at greater intensity than in group C. The survival rate on postoperative day 7 in group C (3/14) was significantly poorer than that in group HS (14/14) ( p < 0.01). The higher survival rate in group HS was accompanied by more rapid recovery of the adenosine triphosphate level and lower serum levels of liver enzymes after reperfusion ( p < 0.01 vs. group C). Heat shock preconditioning induces HSP72 in the rat liver with fibrosis and provides significantly increased tolerance of warm-ischemia reperfusion injury.     

早期自然流产蜕膜组织细胞凋亡与热休克蛋白70、P53的表达

目的观察早期自然流产蜕膜组织细胞凋亡情况及与热休克蛋白70（HSP70）、P53表达的关系。方法采集20例正常早孕人工流产和20例早期自然流产的蜕膜组织，应用末端脱氧核糖核酸转移酶介导的缺口末端标记法（TUNEL）检测蜕膜组织细胞凋亡情况，免疫组织化学法检测蜕膜组织中热休克蛋白70、P53的表达。结果（1）早期自然流产组蜕膜与正常早孕蜕膜组织相比，凋亡显著增加（P〈0．01）；（2）蜕膜组织中HSP70、P53表达，自然流产组与正常早孕组相比显著增强（P〈0．01）。结论蜕膜组织凋亡过度可能为自然流产发生机制之一，蜕膜细胞凋亡的增多与P53表达上调具有一致性；HSP70不能抑制蜕膜细胞凋亡，可能对蜕膜细胞有保护作用。     

热休克蛋白70 mRNA在膀胱癌中的表达及与细胞凋亡的关系

目的　探讨热休克蛋白 70 (HSP 70 )mRNA在膀胱移行细胞癌中的表达及与细胞凋亡的关系。　方法　应用原位杂交法对 6 0例膀胱癌组织中HSP 70mRNA进行检测 ,原位DNA末端标记法 (TUNEL)检测细胞凋亡情况。　结果　 6 0例标本中 ,HSP 70mRNA阳性表达率为 5 6 .7% (34/ 6 0 )。HSP 70mRNA表达随肿瘤分级增高而增加 (P <0 .0 5 ) ;G1,G2 和G3 各级间两两比较 ,HSP 70mRNA表达差异也有显著性意义 (P <0 .0 5 )。随着肿瘤分期增高 ,HSP 70mRNA表达随之增加 (P <0 .0 5 ) ;Ⅰ ,Ⅱ和Ⅲ各期间两两比较 ,差异有显著性意义 (P <0 .0 5 )。肿瘤细胞凋亡指数 (AIs)随恶性程度的增高显著降低 (P <0 .0 5 ) ;HSP 70mRNA表达率和AIs呈负相关 (rs=- 0 .6 85 ,P <0 .0 5 )。　结论　HSP 70mRNA表达随膀胱癌恶性程度增加显著增高 ,细胞凋亡则显著降低 ,提示HSP 70表达能够抑制膀胱癌细胞的凋亡。     

尿胰蛋白酶抑制剂对肝脏保存再灌注中肝窦内皮细胞损伤的保护作用

目的　探讨尿胰蛋白酶抑制剂 (UTI)对肝脏低温保存再灌注中窦内皮细胞损伤的保护作用。方法　应用离体大鼠肝脏保存再灌注模型 ,测定保存 12 h、2 4 h,再灌注 30 min流出液中内皮素 (ET)、丙氨酸转氨酶 (AL T)、天冬氨酸转氨酶(AST)、乳酸脱氢酶 (L DH)的活性、透明脂酸 (HA)的摄取量以及肝组织中髓过氧化物酶 (MPO)水平 ,光镜下观察肝窦内皮细胞的形态学改变 ,比较分析 U TI(10 0 U/ m l)对上述指标的影响。结果　对照组肝脏保存再灌注流出液中 ET含量明显升高 (P<0 .0 5 ) ,HA摄取明显降低 (P<0 .0 5 ) ,并伴随 AL T、AST、L DH、MPO水平显著增高和肝窦内皮细胞形态学的异常改变 ;保存液中加入 UTI后 ,上述指标异常变化均明显减轻 ,其差异具有显著性 (P<0 .0 5 )。结论　 UTI对离体大鼠肝脏窦内皮细胞的保存再灌注损伤有保护作用     

Experimental study of the effects of deletion variant of hepatocyte growth factor on hepatic ischaemia-reperfusion injury

BACKGROUND: Hepatic ischaemia-reperfusion (IR) injury is still a serious complication following liver surgery. The effect of the deletion variant of hepatocyte growth factor (dHGF) on hepatic IR injury was examined in rats. METHODS: Male Wistar rats were divided into two groups after 90 min of partial liver ischaemia: the dHGF group which was given dHGF 0.5 mg/kg intravenously immediately after reperfusion, followed by 0.5 mg/kg every 12 h, and the control group, which received vehicle buffer only. Serum chemistry, histopathological findings and liver weights were compared between the groups. RESULTS: In the dHGF group, the increase in serum alanine transaminase and hyaluronic acid levels was significantly reduced, and the serum albumin level increased after reperfusion. The extent of hepatic necrosis 24 h after reperfusion was decreased in the dHGF group. Moreover, the proportion of terminal deoxynucleotidyl transferase-mediated 2'-deoxyuridine 5'-triphosphate nick end labelling-positive hepatocytes 6 h after reperfusion was reduced in the dHGF group. The non-ischaemic-, ischaemic- and whole-liver weight : body-weight ratio significantly increased in the dHGF group after reperfusion. The proportion of proliferating cell nuclear antigen-positive hepatocytes in the dHGF group markedly increased after 6 h after reperfusion in the non-ischaemic lobes, while in the ischaemic lobes it increased 24 h after reperfusion. CONCLUSION: These data suggest that dHGF not only improves recovery from IR injury, but also accelerates recovery from these injuries. dHGF may be an effective pharmacological agent for prevention and treatment of hepatic IR injury.     

热休克预处理对严重烧伤大鼠胃黏膜的保护作用及机制

目的观察热休克预处理（HS）对严重烧伤大鼠胃黏膜热休克蛋白（HSP）60、HSP70表达及线粒体超氧化物歧化酶（SOD）、细胞色素氧化酶（CCO）活性的影响，探讨HS对严重烧伤大鼠胃黏膜的保护作用及机制。方法将Wistar大鼠随机分为烧伤组（40只）：烧伤后即制作急性胃黏膜损伤模型；另取8只大鼠不致伤作为空白对照。HS组（40只）：于烧伤前20h行HS，另取8只大鼠仅行HS不烧伤，作为实验对照。放线菌素D组（40只）：在HS前30min静脉注射放线菌素D0．1mg／kg，随后的处理同HS组；另取8只大鼠只注射放线菌素D不烧伤，作为实验对照。于伤后3、6、12、24、48h处死各组大鼠（每组每时相点8只）。取胃黏膜组织检测胃黏膜损伤指数（UI）、HSP70 mRNA、HSP60、HSP70的表达及SOD、CCO的活性。结果大鼠烧伤后uI呈时间依赖性增加，烧伤组伤后24h胃黏膜损伤程度最严重，UI为12．8±1．9。除伤后3h外，HS组大鼠各时相点uI均低于烧伤组（P＜0．05或0．01）。放线菌素D组大鼠胃黏膜损伤程度明显重于烧伤组及HS组（P＜0．05）。烧伤组、HS组除伤后24、48h外其余各时相点HSP70 mRNA均增加，而放线菌素D组伤后24、48h有所增加。与烧伤组比较，HS组大鼠胃黏膜HSP60及HSP70表达显著增加，除伤后48h外其余各时相点比较，差异均有统计学意义（P＜0．05或0．01）。放线菌素D组大鼠HSP60和HSP70表达明显受抑（P＜0．05）。大鼠烧伤后胃黏膜CCO、SOD活性不断降低，经HS后CCO及SOD下降不明显，在伤后6、12、24h均高于同时相点烧伤组（P＜0．05或0．01）。结论HS对大鼠严重烫伤后急性胃黏膜损害具有保护作用，其机制可能与HSP60、HSPT0诱导表达增强，线粒体SOD及CCO活性增加等有关。     

持续低温氧合机械灌注对小鼠心脏死亡器官捐献供肝的保护作用

目的研究体外持续低温氧合机械灌注对小鼠心脏死亡器官捐献(donation after cardiac death,DCD)供肝的保护作用。方法雄性ICR小鼠根据灌注保存方式不同分为新鲜供肝低温保存组(FC组)、DCD供肝低温保存组(DC组)和DCD供肝低温氧合机械灌注组(DP组),每组6只。低温灌注保存供肝6h后,收集保存过供肝的威斯康星大学保存液(University of Wisconsin solution,UW液),检测丙氨酸转氨酶(ALT)和天冬氨酸转氨酶(AST)水平。收集3组小鼠肝组织,切片,行常规苏木素-伊红(HE)染色,在光学显微镜下观察病理改变,用原位末端脱氧核苷酸转移酶标记法介导的dUTP缺口末端标记(terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling,TUNEL)法观察3组小鼠肝细胞凋亡情况。结果保存6h后,DC组与DP组的UW液中的ALT、AST含量均明显高于FC组(均为P<0.01);DP组的ALT和AST含量均明显低于DC组(均为P<0.01)。光学显微镜下,FC组未见明显坏死区域,DC组肝细胞损伤严重,DP组肝组织未见明显损伤及坏死。荧光显微镜下,FC、DP两组肝细胞凋亡程度轻微,DC组肝细胞形态极不规则,肝细胞坏死严重。结论持续低温氧合机械灌注可减轻肝细胞损伤和凋亡,为DCD肝移植的器官保存研究提供了新的方法。     

Welcoming a New Hip into the Family

ABSTRACT

Introduction: The aim of this study is to evaluate whether hemorrhage and resuscitation affect liver, intestinal, and renal expressions of heat shock protein 70 (HSP70), inducible nitric oxide synthase (iNOS), and apoptosis indexes (TUNEL, caspase-3 activation) and whether the expression of these proteins can be modulated by pyrrolidine dithiocarbamate (PDTC) after a nonlethal hemorrhagic shock (HS) in rats. Methods: Forty rats were randomized into four groups: sham-operated, only HS, HS/resuscitation with blood plus normal saline (NS), and HS/resuscitation with blood/NS plus PDTC, 15 mg/kg body weight, intravenously. Rats were subjected to HS by blood removal to a mean arterial pressure of 35–40 mmHg through the femoral artery. After 1 hr of shock, the animals were resuscitated according to the experimental protocol. HSP70, iNOS, cleaved caspase-3 expression, and TUNEL were analyzed in liver, small intestine, and kidney 3 hr after resuscitation. Results: HS upregulated HSP70, iNOS, cleaved caspase-3 expression, and induced apoptosis (TUNEL) (p < .05 to < .001). Resuscitation was not associated with further increase of their expressions. The administration of PDTC during resuscitation decreased liver, intestinal, and renal activation of iNOS and apoptosis indexes (p < .05 to < .001), and was associated with further increase in HSP70 expression (p < .05). Conclusions: Our results show that HS resuscitation with PDTC modulates several signaling pathways (HSP70, iNOS, TUNEL, and caspase-3) in a rat model. The results suggest that PDTC administration—by reducing apoptosis and iNOS expression—may have a potential role in minimizing organ damage after severe hemorrhage.