Unfractionated heparin attenuates intestinal injury in mouse model of sepsis by inhibiting heparanase

Intestinal injury is a key feature in sepsis. Heparanase, a heparin sulfate-specific glucuronidase, mediates the onset of organ injury during early sepsis. Heparin has the function to attenuate inflammation and injury induced by multiple factors; however, whether unfractionated heparin (UFH) can attenuate the intestinal injury induced by sepsis as well as the underlying mechanism is still unknown. In the present study, the function of UFH in intestinal injury induced by sepsis was explored. Results of our study showed that after CLP operation, the inflammatory response and expression of heparanase were increased and NF-κB and MAPK P38 signaling pathways were activated. However, pretreatment with UFH will inhibit the expression and activation of heparanase, and reverse the activation of NF-κB and MAPK P38 signaling pathways, thus attenuating inflammatory responses induced by sepsis. These results suggest that UFH may be a promising therapeutic drug for intestinal injury caused by sepsis.     

The effects of hepatic ischemia/reperfusion injury on postoperative cognitive function in aged rats

IntroductionHepatic ischemia/reperfusion injury (I/R) is a significant source of morbidity and mortality after liver surgery. The aim of this study was to investigate the effect of hepatic I/R injury on the hippocampus in rats with postoperative cognitive dysfunction (POCD).Material and methodsAdult male Sprague-Dawley rats (n = 160, age: 20–25 months, weight: 300–350 g) received I/R surgery with ischemia for 20 min, 30 min, and 40 min in different groups. Behavior tests of the Morris water maze (MWM) test and the passive avoidance test were applied. Population spike (PS) of pyramidal cells, nuclear factor κB (NF-κB) and protein kinase γ (PKCγ) in the hippocampus were observed.ResultsWithin 10 days after surgery, in aged rats with varying impaired cognitive function, spike size and spike latency period were reduced, level of PKCγ was decreased and an increased level of NF-κB was observed in the I/R group, especially in the I/R group with ischemia for 40 min. The parameters showed no significant difference in rats in the I/R group compared with the sham group at the 18^th day after surgery.ConclusionsHepatic I/R injury has a negative impact on the postoperative cognitive function in aged rats, leading to hippocampus changes with PS abnormity and level changes of NF-κB, PKCγ. However, this cognitive deficit improved over time.     

Blocking HMGB1 signal pathway protects early radiation-induced lung injury

It has been reported that HMGB1 participated in various types of lung injury. In this study, we explored whether blocking HMGB1 has a preventive effect on the early radiation-induced lung injury and investigate the mechanism. Mice model of radiation-induced lung injury were accomplished by a single dose irradiation (15 Gy) to the whole thorax. Irradiated mice were treated with HMGB1-neutralizing antibody intraperitoneally dosed 10 μg, 50 μg, 100 μg/mouse respectively and were sacrificed after one week post-irradiation. Lung tissue slices were stained by H&E, and alveolitis was quantified by Szapiel scoring system. The level of cytokines TNF-γ in bronchoalveolar lavage fluid was detected by ELISA method. And p65NF-κB, p50NF-κB protein expression in mice lung tissues was detected by Western blot analysis. The results showed that blocking HMGB1 inhibited the inflammatory response, and thereby decreased the degree of alveolitis of irradiated lung tissue. In addition, HMGB1 antagonist can restrain the expression of type Th2 or Th17 derived inflammatory cytokines TNF-α, IL-6 and IL-17A, promote the expression of Th1 type cytokines INF-γ, and inhibit p65 NF-κB but promote p50 NF-κB activation, which promoted the resolution of the radiation-induced inflammatory response. In conclusion, blocking HMGB1 can reduce the degree of early radiation-induced lung injury, and its mechanism may be related to the promotion of p50NF-κB activation and its downstream molecules expression. Inhibiting HMGB1 may be a new target to deal with early radiation-induced lung injury.     

Protective effects of pentoxifylline on acute liver injury induced by thioacetamide in rats

Pentoxifylline (PTX) is a non-selective phosphodiesterase inhibitor with the effects of antioxidation, anti-inflammation and anti-fibrosis that has been shown to induce damage in liver. The purpose of this study is to investigate the effects and possible mechanisms of PTX on thioacetamide (TAA)-induced acute liver injury in rats. Male Sprague-Dawley (SD) rats were divided into four groups: control, PTX, TAA and PTX+TAA treated groups. Rats were administrated TAA together with or without PTX for a week and sacrificed 24 h after the last intragastric administration of PTX. Histopathological analysis was carried out. The liver function, the indices of oxidative stress including malondialdehyde (MDA), superoxide dismutase (SOD), and glutathione (GSH) in liver tissues, and pro-inflammatory cytokines expressions were examined. The mRNA level of NF-κB p65 in liver was also determined. PTX significantly attenuated TAA-induced liver injury. The serum transaminase and MDA levels were reduced while the levels of SOD and GSH were increased, as compared with the TAA-treated group. PTX also remarkably suppressed the secretions of pro-inflammatory cytokines and the nuclear factor-κB (NF-κB) activation induced by TAA. In addition, the histopathological analysis showed that the range and degree of liver tissue lesions were improved obviously in PTX treated group. Pentoxifylline could ameliorate the effects of thioacetamide-induced acute liver injury in rats by inhibiting oxidative stress, expressions of pro-inflammatory cytokines and NF-κB activation.     

Protective effects of bifidobacterial adhesin on intestinal mucosa of stressed male rats via modulation of inflammation

This study aimed to assess BA impact on inflammation markers and repair of intestinal mucosa. Forty-eight rats were randomly divided into stress (n = 24) and BA (n = 24) groups. Stress was induced by fettering in all animals, fed enterally with 125.4 kJ/kg/d and 0.2 g/kg/d nitrogen. Then, rats were treated for 8 days with 5 mg/kg/d BA (BA group) or 5 mg/kg/d saline (Stress group). Levels of NF-κB, IL-10, TNF-α, and IFN-γ were measured at different time points, in plasma and intestinal mucosa samples. Changes in intestinal mucosa morphology were observed by electron microscopy. Plasma and/or mucosal levels of NF-κB, TNF-α, and IFN-γ were significantly higher in both groups after stress induction (P < 0.05). These high levels persisted in control animals throughout the experiment, and were significantly reduced in the BA group, 3 and 8 days after stress induction (P < 0.05). Interestingly, IL-10 levels were increased after BA treatment (P < 0.05). At day 8, ileal mucosal villi and crypt structure were significantly restored in the BA group. Bifidobacterial adhesin plays a role in repairing intestinal mucosa injury after stress by regulating the release of inflammatory mediators in the intestinal mucosa.     

大鼠小肠缺血预适应对缺血-再灌注损伤保护作用及机制

目的:探讨小肠缺血预适应(ischemic preconditioning,IP)对缺血再灌注(ischemia／reperfusion,I／R)肠黏膜损伤的保护作用及可能机制。方法:以大鼠肠系膜前动脉制造I／R和IP模型;用分光光度法测血和肠组织二胺氧化酶(diamine oxidase,DAO)活性;用H-E和PAS特染显示肠黏膜的病理改变并进行Chiu CJ评分;用免疫组化方法显示肠绒毛CGRP、NPY肽能神经并用测微尺测定阳性神经纤维密度。结果:与对照组相比,I／R组及IP I／R组血DAO水平升高而肠黏膜DAO水平降低,肠黏膜损伤Chiu CJ评分数升高;肠绒毛CGRP阳性神经纤维密度降低而NPY阳性神经纤维密度升高;但IP轻于I／R的变化。结论:小肠IP能减轻I／R引起的肠黏膜机械屏障的组织病理损伤,其机制是通过肠黏膜局部CGRP、NPY肽能神经参与调节其微血管舒缩平衡而实现的。     

Ginsenoside Rg1 alleviates acute liver injury through the induction of autophagy and suppressing NF-κB/NLRP3 inflammasome signaling pathway

Background: Severe hepatitis is a common cause of chronic or acute liver disease and autophagy might play an important role in cellular response to inflammation and injury. It has been reported that Ginsenoside-Rg1 (G-Rg1) has strong hepatoprotective effects for acute liver injury, but its protective mechanisms have not yet been elucidated. This study aims to explore the detailed molecular mechanisms of G-Rg1 on acute liver injury via autophagy.Methods: The role of G-Rg1 by autophagic induction was studied in the mouse model of acute liver injury which induced by carbon tetrachloride (CCl4). Liver function, inflammatory reaction and apoptosis were detected when autophagy has been inhibited by 3-MA or stimulated by RPA. MCC950 and ATP were applied to investigate the role of NLRP3 inflammasome in acute liver injury. The differential expression of NF-κB, NLRP3 inflammasome, caspase 1, caspase 3, IL-1β, IL-18, LC3-I, LC3-II, Beclin-1, PINK1 and Parkin have been detected by the quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot.Results: G-Rg1 could decrease ALT, AST, TNF-α, IL-1β and IL-6 in mice with CCl4-induced acute liver injury. The change of autophagy and apoptosis after the treatment of 3-MA or RPA demonstrated that the autophagy played a key role in the protective effect of G-Rg1 in acute liver injury. The enhancement of G-Rg1 promoted-autophagy resulted in the significant decrease in NF-κB, NLRP3 inflammasome, caspase 1, caspase 3, IL-1β and IL-18, which suggesting that NF-κB/NLRP3 inflammasome signaling pathway was associated with the autophagy induced by G-Rg1 in acute liver injury.Conclusion: G-Rg1 ameliorated acute liver injury via the autophagy, which may be related to NF-κB/NLRP3 inflammasome signaling pathway.     

猕猴肠缺血再灌注激活了补体旁路途径

补体激活是炎症反应放大的重要环节之一。本文通过猕猴肠缺血再灌注(IIR)的实验,探讨由此发展的多器官功能障碍综合征(MODS)究竟是通过何种途径激活补体?以增加对全身炎症反应内源性保护机制的认识。通过肠系膜上动脉夹闭—松解术分别造成5只猕猴肠缺血再灌注损伤,采用免疫速率散射比浊法、CH50总补体测定法测定血C3、C4、C-反应蛋白(CRP)、总补体的变化,免疫细胞化学观察中性粒细胞(PMN)上IL-1、NF-κB变化,流式细胞仪测定PMN凋亡率。IIR后24 h,体内总补体由(106.6±18.07)U/ml降至(62.1±9.52)U/ml,P>0.05;其中,C3下降了30%,P>0.05;C4在IIR前后无明显变化(0.1342±0.07 vs 0.1420±0.06,P>0.05)。PMN的凋亡率由IIR前的15.4%±1.41%显著降低至IIR后3.5%±0.53%,P>0.05,其IL-1、NF-κB表达增加;CRP由IIR前的(4.33±1.31)mg/L增加至IIR后的(17.73±0.86)mg/L,P>0.01。IIR后补体通过旁路途径激活,活化补体片段抑制PMN凋亡,增加急性时相炎症蛋白如CRP、IL-1的表达,使炎症放大至全身,推动了MODS的发生。     

Emulsified isoflurane preconditioning reduces lung injury induced by hepatic ischemia/reperfusion in rats

Objective: To investigate whether emulsified isoflurane preconditioning could reduce lung injury induced by hepatic I/R in rats and its mechanism.Materials and methods: 32 pentobarbital-anesthetized Sprague-Dawley rats were equally randomized into four groups: laparotomy group (Sham group), hepatic I/R and normal saline infusion group (I/R+S group), I/R and lipid vehicle infusion (I/R+V group), or I/R and 8% emulsified isoflurane infusion (I/R+E group) at the rate of 8 ml·kg^-1·h^-1 for 30 min. Blood supply of the hepatic artery and portal vein to the left and the median liver lobes was occluded for 90 min after 30-min washout time. Reperfusion was allowed to proceed for 4 h before sacrifice of the animals. Lung injury was observed histologically. Neutrophil infiltration and TNF-α concentration in serum and lung were measured. Changes of wet-to-dry weight ratios in lung tissue, ICAM-1 expression and NF-κB activity in lung after hepatic I/R were determined.Results: Compared with I/R+S or I/R+V group, emulsified isoflurane preconditioning reduced hepatic I/R-induced lung histologic injury and inhibited the increase of myeloperoxidase (MPO) activity in the lung tissue markedly (5.5±1.37 and 5.22±1.33 vs 3.81±1.62 U/g, P<0.05). In addition, both serum and lung tissue TNF-α levels were reduced in I/R+E group (104.58±31.40 and 94.60±22.23 vs 72.44±17.28 pg/ml, P<0.05; 393.51±88.22 and 405.46±102.87 vs 292.62±74.56 pg/ml, P<0.01). Emulsified isoflurane preconditioning also inhibited the increase of ICAM-1 expression (0.79±0.17 and 0.84±0.24 vs 0.62±0.21, P<0.05) and NF-κB translocation (4.93±0.48 and 4.76±0.57 vs 4.01±0.86, P<0.05) in the lung tissue markedly.Conclusions: Emulsified isoflurane preconditioning markedly attenuated hepatic I/R-induced lung injury in rats, which may be hopefully applied to the clinical treatment of organ injury caused by hepatic surgery, transplantation or hemorrhagic shock.     

三七总皂苷抑制铁死亡和炎症反应减轻大鼠脑缺血再灌注损伤

目的:基于三七总皂苷(PNS)对铁死亡和炎症反应的调控作用,探讨PNS抗脑缺血再灌注损伤(CIRI)机制。方法:采用大脑中动脉阻塞/复灌注(MCAO/R)方法建立大鼠CIRI模型,PNS干预后,各组大鼠进行Longa评分比较;观察脑梗死体积;试剂盒检测缺血侧大脑皮质组织中Fe2+、GSH、MDA、IL-1β、TNF-α和IL-6含量;Western blot检测脑组织中铁死亡关键调控蛋白谷胱甘肽过氧化物酶4(GPX4)的表达水平。结果:MCAO/R后,大鼠神经评分显著增加,有明显脑梗死区,皮层组织中Fe2+和MDA及IL-1β、TNF-α、IL-6含量显著增加,而GSH含量和GPX4水平显著降低。与MCAO/R组相比,PNS干预组大鼠神经功能评分显著降低、脑梗死体积减小、脑组织中Fe2+和MDA及IL-1β、TNF-α、IL-6含量显著降低,而GSH含量和GPX4水平显著增加。结论:PNS可有效减轻CIRI,其机制与抑制铁死亡和炎症反应有关。     

肠缺血后处理抑制大鼠肠缺血再灌注所致的急性肺损伤

目的： 研究肠缺血后处理对大鼠肠缺血再灌注（I/R）所致急性肺损伤的影响及机制。 方法： 40只SD大鼠随机分为5组（n=8）：假手术组（对照组）,仅分离而不阻断肠系膜上动脉（SMA）;肠I/R损伤组,阻断SMA 1 h后再灌注1 h;缺血预处理（IPC）组,在长时间阻断SMA前预先阻断SMA 10 min然后开放 10 min;缺血后处理（IPo）组,在阻断SMA 1 h后连续进行3个循环的开放 SMA 30 s /阻断SMA 30 s (总时间为3 min),然后开放1 h;延迟后处理（delay）组,在再灌注3 min （IPo的总时间）后行3个循环的 30 s 缺血/ 30 s再灌注的缺血后处理,余同IPo组。监测平均动脉压（MAP）,于再灌注1 h 后取肺组织光镜下观察肺形态学的变化,检测血清及支气管肺泡灌洗液蛋白含量并计算肺通透性指数,称肺湿重及干重并计算肺含水率,检测肺组织丙二醛（MDA）的含量,超氧化物歧化酶（SOD）及髓过氧化物酶（MPO）的活性,检测血清TNF-α及IL-6的浓度。结果： 缺血后处理与预处理都能显著改善肺损伤,显著降低肺通透性指数及肺含水率,同时降低血浆TNF-α与IL-6的浓度、肺组织MDA含量及MPO活性,升高SOD活性。后处理被延迟3min后,其肺保护作用消失,且不能显著改变上述指标。 结论： 缺血后处理与预处理都具有抗肠I/R后肺损伤的作用,可能与其清除氧自由基、抑制中性粒细胞的肺内聚集及炎症细胞因子的释放有关;而且,再灌注早期后处理对肺的保护作用最关键。     

Apelin-13对离体缺血/再灌注大鼠心脏损伤的影响

目的观察apelin-13对离体大鼠缺血/再灌注心脏损伤的影响,并初步探讨其对apelin受体APJ(putative re-ceptor protein related to the angiotensin receptorAT1)及细胞信号Akt1/2的影响。方法Langendorff装置恒流灌注大鼠离体心脏,采用停灌/复灌方式复制缺血/再灌注模型;观察缺血/再灌注期间心脏收缩期左心室内压上升的最大变化速率( LVdp/dtmax)及舒张期左心室内压下降的最大变化速率(-LVdp/dtmax);RT-PCR和Western blot测定组织中APJ受体mRNA和Akt1/2蛋白的表达情况。结果Apelin-13可以增加缺血/再灌注损伤心脏的±dp/dtmax(P<0·01);可以明显增强心肌组织中Akt1/2的表达;缺血/再灌注可以引起心肌组织中APJ受体表达上调。结论Apelin-13拮抗缺血/再灌注引起的心脏收缩及舒张功能障碍;可能与组织中APJ受体表达上调引起Akt1/2表达增强有关。     

Wortmannin,PI3K/Akt signaling pathway inhibitor,attenuates thyroid injury associated with severe acute pancreatitis in rats

Increasing evidences suggest that PI3K/AKT pathway plays an important role in the pathogenesis of inflammatory diseases such as acute pancreatitis. However, the exact effect of PI3K/AKT on thyroid injury associated with acute pancreatitis has not been investigated. This study aimed to investigate the protective effects of wortmannin, PI3K/AKT inhibitor, on thyroid injury in a rat model of severe acute pancreatitis (SAP). Sixty male SD rats were randomly divided into four groups: sham operating group (SO), SAP group, wortmannin treatment (WOR) group and drug control (WOR-CON) group. Serum amylase (AMY), lipase (LIP) and thyroid hormone levels were evaluated. The morphological change of thyroid tissue was analyzed under the light and transmission electron microscopy. AKT, P38MAPK and NF-κB expression in the thyroid tissue was evaluated by immunohistochemical staining. Oxidative stress and inflammatory cytokines were detected. Results showed that wortmannin attenuated the following: (1) serum AMY, LIP and thyroid hormone (2) pancreatic and thyroid pathological injuries (3) thyroid MDA, (4) thyroid ultrastructural change, (5) serum TNF-α, IL-6 and IL-1β (6) AKT, MAPKP38 and NF-κB expression in thyroid tissues. These results suggested that wortmannin attenuates thyroid injury in SAP rats, presumably because of its role on prevent ROS generation and inhibits the activation of P38MAPK, NF-κB pathway. Our findings provide new therapeutic targets for thyroid injury associated with SAP.     

姜黄素对脓毒症急性肺损伤的炎性反应及Notch2/Hes-1通路的影响

目的探讨姜黄素对脓毒症急性肺损伤的炎症反应及对Notch2/Hes-1通路的影响。方法36只Wistar大鼠随机分为正常对照组、模型组及姜黄素干预组。HE染色观察各组大鼠肺组织病理学改变;测量各组大鼠肺组织湿/干重(W/D)比。酶联免疫吸附法(ELISA)检测各组大鼠血清肿瘤坏死因子-α(TNF-α)与细胞间黏附分子-1(ICAM-1)水平;采用免疫组织化学方法与Western blot方法检测各组大鼠肺组织Notch2与Hes-1蛋白的表达。结果LPS诱导的急性肺损伤大鼠肺组织严重出血且有明显的炎性细胞浸润,血清TNF-α与ICAM-1水平显著升高;而给予姜黄素干预后,急性肺损伤大鼠肺组织炎性明显减轻,血清TNF-α与ICAM-1水平显著降低(P<0.01)。免疫组织化学结果与Western blot结果显示,模型组大鼠肺组织Notch2与Hes-1蛋白表达的平均光密度值显著升高(P<0.01);而给予姜黄素干预后,急性肺损伤大鼠肺组织Notch2与Hes-1蛋白表达的平均光密度值显著降低(P<0.01)。结论姜黄素能够减轻脓毒症急性肺损伤大鼠的炎性反应,其机制可能与Notch2/Hes-1通路相关。     

Hydrogen sulfide protects against amyloid beta-peptide induced neuronal injury via attenuating inflammatory responses in a rat model

Neuroinflammation has been recognized to play a critical role in the pathogenesis of Alzheimer''s disease (AD), which is pathologically characterized by the accumulation of senile plaques containing activated microglia and amyloid β-peptides (Aβ). In the present study, we examined the neuroprotective effects of hydrogen sulfide (H₂S) on neuroinflammation in rats with Aβ1-40 hippocampal injection. We found that Aβ-induced rats exhibited a disorder of pyramidal cell layer arrangement, and a decrease of mean pyramidal cell number in the CA1 hippocampal region compared with those in sham operated rats. NaHS (a donor of H₂S, 5.6 mg/kg/d, i.p.) treatment for 3 weeks rescued neuronal cell death significantly. Moreover, we found that H₂S dramatically suppressed the release of TNF-α, IL-1β and IL-6 in the hippocampus. Consistently, both immunohistochemistry and Western blotting assays showed that H₂S inhibited the upregulation of COX-2 and the activation of NF-κB in the hippocampus. In conclusion, our data indicate that H₂S suppresses neuroinflammation via inhibition of the NF-κB activation pathway in the Aβ-induced rat model and has potential value for AD therapy.     

大鼠肠缺血-再灌注损伤中FGFR2表达的规律

目的观察酸性成纤维细胞生长因子受体2（acid fibroblast growth factor receptor,FGFR2）在肠缺血-再灌注损伤中表达规律。方法以大鼠肠系膜上动脉（SMA）夹闭造成肠缺血-再灌注损伤模型,并将动物随机分为假手术组（C组）、生理盐水对照组（R组）、改构体aFGF治疗组（F组）。除假手术组外,其余各组动物均于缺血45min后于2、6、12、24h活杀,取小肠组织标本,免疫组化和RT—PCR检测FGFR的表达规律。结果在正常大鼠,FGFR分布在小肠绒毛上皮细胞的肠腔侧、侧壁和小肠隐窝朝向隐窝腔的-侧的细胞膜上。缺血和再灌注的初期,FGFR的表达未发生明显变化,随着再灌注时间的延长逐渐增强。FGF使FGFR的表达有明显的增强和提前表达。缺血和再灌注使FGFRmRNA的表达迅速增加,在再灌注后6h达到高峰。F组FGFRmRNA的表达较R组相应时间点显著增加（P〈0．05）。结论FGFR在肠缺血-再灌注损伤的修复中起积极作用。     

Favourable effects of whey protein on acetic acid-induced ulcerative colitis in a rat model

IntroductionIn the present study, we aimed to examine the effects of the administration of whey protein through rectal enema to rats with acetic acid-induced ulcerative colitis on the pathways of nuclear-related factor-2 (Nrf-2), haem oxygenase-1 (HO-1), nuclear factor κB (NF-κB), active protein kinase-1 (AP-1), tumour necrotising factor-α (TNF-α), and cyclooxygenase-2 (COX-2), IL-6, IL-10.Material and methodsTwenty-eight rats were employed for the trial. Ulcerative colitis was induced through the use of acetic acid. The therapeutic doses of whey protein were administered rectally. Ulcerative colitis was subjected to histopathological examination and protein levels in colon tissue were measured with the Western blot method.ResultsThe significant increases observed in the levels of AP-1, COX-2, IL-6, IL-10, NF-κB, and TNF-α as markers of inflammation following the development of ulcerative colitis showed remarkable decreases along with the administration of whey protein (p < 0.05). On the other hand, we identified a decrease in the Nrf2-ARE signal pathway and HO-1 protein having protective roles in the colon inflammatory response along with the development of ulcerative colitis and activation of the Nrf2-HO-1 pathway by the whey protein.ConclusionsWhey protein modulates Nrf2/HO-1 and NF-kB pathways, thereby creating a therapeutic effect against colonic inflammation induced by acetic acid (AA) due to its anti-inflammatory effects.     

Astrocytic response in the rodent model of global cerebral ischemia and during reperfusion

The present study investigated alterations in astrocytic cells after global cerebral ischemia resulting from cardiac arrest immediately and at several intervals after reperfusion when excessive formation of highly cytotoxic free radicals is known to occur. The cellular fraction of astrocytic origin (glial plasmalemmal vesicles - GPV) was examined by biochemical and immunochemical procedures. A tendency towards an elevation in immunocontent of glial fibrillary acidic protein (GFAP) was noticed after 24 hours whereas a significant increase was observed 7 days post ischemic event. The features of astrocytic stimulation were also observed in electron microscopy studies. An enhanced amount of gliofilaments was noticed in brain sections obtained from rats after 7 days of recovery. Simultaneously, a gradual decrease of total glutathione level, depending on the duration of reperfusion, was observed in brain homogenates and in fractions of astroglial origin. The most considerable reduction was observed on day 1 (52%) and day 7 (65%) after reperfusion in brain homogenates and on day 7 (47%) in GPV fraction. The results indicate an enhanced reactivity of astrocytic cells in ischemic conditions concomitantly with a long lasting decrease of total glutathione. Obviously, the inability of astrocytic glutathione system to detoxify free radicals formed during ischemic/reoxidation conditions may lead to damage to cerebral neurons by oxidative stress.     

右美托咪定通过抑制内质网应激反应减轻肺缺血/再灌注小鼠肾损伤

目的:评价右美托咪定(dexmedetomidine,DEX)通过抑制内质网应激反应减轻小鼠肺缺血/再灌注(I/R)诱发肾损伤的机制。方法:雄性健康SPF级C57BL/6J小鼠50只,体重20~24 g,8~10周龄,随机分为5组(n=10):假手术组(sham组)、I/R组、阿替美唑(atipamezole,Atip)组、DEX组和DEX+Atip组。采用小鼠在体左侧肺门夹闭30 min再灌注180 min方法制备肺缺血/再灌注损伤(I/R)模型。Atip组、DEX组和DEX+Atip组分别在肺门阻断前30 min腹腔注射Atip(250μg/kg)、DEX(20μg/kg)和DEX+Atip,其余处理同I/R组。再灌注结束后眼眶采血检测血肌酐与尿素氮浓度,取肾组织光镜下观察肾细胞的形态学改变,检测caspase-3的酶活性,TUNEL法检测肾细胞凋亡指数,Western blot和RT-PCR检测c-Jun氨基末端激酶(JNK)、caspase-12、CCAAT/增强子结合蛋白同源蛋白(CHOP)和葡萄糖调节蛋白78(GRP78)的蛋白及mRNA水平。结果:与假手术组相比,其余组光镜下肾组织有明显损伤,血肌酐与尿素氮、肾细胞凋亡指数、caspase-3酶活性、JNK、caspase-12、CHOP和GRP78的蛋白及mRNA水平均升高(P0.01)。与I/R、Atip组和DEX+Atip组相比,DEX组光镜下可见肾细胞损伤减轻,血肌酐与尿素氮、肾细胞凋亡指数、caspase-3酶活性、JNK、caspase-12和CHOP表达均有下降,GRP78表达升高,差异有统计学意义(P0.01)。结论:右美托咪定预先给药可减轻小鼠肺缺血/再灌注诱发的肾损伤,其机制可能与激动α2-肾上腺素能受体,抑制内质网过度应激有关。     

紫檀芪对小鼠缺血性脑损伤的神经保护机制研究

目的:探索紫檀芪(PTE)对小鼠缺血性脑损伤中的保护作用及机制。方法:将C57雄性C57BL/6J小鼠分为假手术组(sham)、脑缺血再灌注损伤组(IR)、紫檀芪治疗组(PTE+IR)和紫檀芪阻断剂Zn PP抑制紫檀芪治疗组(PTE+Zn PP+IR),其中PTE的剂量为5 mg/kg,于脑缺血再灌注损伤(IR)前连续5 d每天腹腔给药1次,Zn PP以3 mg/kg的剂量于IR前30 min及IR后24 h分别腹腔给药1次;然后于缺血性脑损伤后0、2、12、24 h及48 h (IR0、IR2、IR12、IR24 h及IR48 h)对小鼠进行神经行为学评分;最后于IR48 h对小鼠进行干湿比重法脑水含量测定,TUNEL试剂盒检测细胞凋亡,Western Blot检测caspase-3及cleaved caspase-3蛋白的表达。结果:PTE可降低缺血性脑损伤后小鼠神经行为学评分、减轻脑水含量、降低细胞凋亡率及下调凋亡蛋白cleaved caspase-3的表达而保护神经细胞,但是PTE的这些神经保护作用可被其抑制剂Zn PP逆转。结论:PTE在鼠脑缺血再灌注损伤中具有明确的保护作用...