麝香保心丸对缺血再灌性损伤大鼠心肌的保护作用

为了探讨麝香保心丸对动物心肌缺血再灌性损伤的保护作用，本文采用wistar大鼠建立缺血再灌损伤模型，测定了心肌坏死面积，心脏血流动力学等指标，实验结果表明：预防性给予麝香保心丸具有缩小心肌坏死面积（P＜0．01）；提高Vmax，Vce40（P＜0．05）。

心肌缺血-再灌注损伤与氧自由基关系的研究

目的:探讨氧自由基与心肌缺血-再灌注损伤的关系。方法:采用在体大鼠心肌缺血-再灌注模型,于结扎冠状动脉前3m in,静注超氧化物歧化酶(SOD)75U/kg或等体积生理盐水(N S),观察心肌缺血-再灌注状态下心电图、心肌丙二醛(MDA)、SOD及Ca2+的变化。结果:在缺血期,8/20动物发生心律失常。再灌后,缺血再灌组全部动物发生室性心律失常,其中90%为新发生或再灌后加重的心律失常,室性早博、室速、室颤发生率分别为100%、80%和40%;心肌MDA含量明显高于假手术组(P<0.01);SOD活性从11.4±2.9降至6.9±1.6mm o l/m in.g.port(P<0.01),Ca2+含量由1.6±0.1增至2.0±0.2μm o l/g(P<0.01)。结论:心肌缺血-再灌注损伤与再灌后产生大量氧自由基有关。SOD可使室性心律失常发生率明显减少;降低MDA和Ca2+的含量。

脂质过氧化在再灌流性肝损伤中的作用

采用低流率-再灌流模型研究脂质过氧化在再灌流性肝损伤中的作用,肝脏经过90min低速率灌流未见明显损伤,当灌流速率恢复到正常后中心静脉周围区(PC区)细胞发生迅速不可逆损害,并伴有丙二醛生成率大幅度上升,低速率灌流期间,灌流液中黄嘌呤与次黄嘌吟浓度由原来的1.5和3.6μmol·L^(-1)逐步升高至5.5和11.5μmol·L^(-1),自由基清除剂儿茶酸能使再灌流期丙二醛生成率由295 nm01·g^(-1)·h^(-1)下降至109 nmol·g^(-1)·h^(-1),并使LDH释放率减少约50％,PC区细胞死亡率减少89％,再灌流初期用氮饱和灌流液冲洗3 min,使再灌流所致的LDH释放下降约50％,PC区细胞死亡率减少84％,别嘌吟醇(2～6mmol·L^(-1))对防止再灌流性肝损伤表现出明显的剂量效应关系。 与预计结果相反低浓度别嘌呤醇(0.5～1mmol·^(-1))能增加再灌流性肝损伤,400μmol·L^(-1)黄嘌呤则使再灌流性肝损伤明显减轻,其代谢产物尿酸对降低再灌流时丙二醛生成率以及细胞损害均表现出明显的剂量反应关系。

水蛭注射液对大鼠脑缺血再灌注后TNF-α、IL-lβ和ICAM-1蛋白表达的影响

目的：观察水蛭注射液对大鼠局灶性脑缺血再灌注损伤后TNF-α、IL-1β和ICAM-1表达的影响，以探讨水蛭注射液对脑缺血再灌注损伤的保护机制。方法：96只健康Wistar大鼠随机分为假手术组、模型组、丹参对照组、水蛭注射液组。采用线栓法制作大鼠脑缺血再灌注损伤模型，规定时间取脑标本，检测相关指标。结果：再灌注3h后脑组织TNF-α、IL-1β和ICAM-1含量明显升高，水蛭注射液可以明显降低脑组织TNF-α、IL-1β和ICAM-1含量（P〈0．01～0．05）。结论：水蛭注射液可降低炎性细胞因子TNF-α、IL-1β和ICAM-1的表达，抗脑缺血后炎症反应，从而起到脑保护作用。

EFFECTS OF ELECTROACUPUNCTURE ON EXPRESSION OF INTERCELLULAR ADHESION MOLECULE-1 IN THE RAT OF LOCAL CEREBRAL ISCHEMIA-REPERFUSION

Objective To investigate effects of electroacupuncture （EA） on expression of intercellular adhesion molecule-1 （ICAM-1） in the rat of local cerebral ischemia-reperfusion. Methods Eighty SD rats were randomly divided into a normal control group, a sham operation group, a model group and an EA treatment group, 20 rats in each group. The thread-obstruction method was used for preparation of ischemia-reperfusion model. Zea-Longa rating criteria were used for evaluation of nervous function disorder; Immunohistochemical SABC method was used for detection of ICAM-1 expression in the microvascular endothelial cell of the ischemic brain region, and ELISA method for the soluble ICAM-1 （slCAM-1） content in peripheral blood. Re. suits After cerebral ischemia-reperfusion, both ICAM-1 expression level in the microvascular endethelium cell of the ischemic brain region and slCAM-1 content in the peripheral blood significantly increased in the model group as compared with the normal group and the sham operation group （P〈0.01）; After EA treatment, the ICAM-1 expression level in the microvascular endothelial cell of the ischemic brain region and slCAM-1 content in the peripheral blood were significantly down-regulated in the EA treatment group as com- pared with the model group （P〈 0.05）. Conclusion After cerebral ischemia-reperfusion, the microvascular endothelial cell of the ischemic brain region releases ICAM-1, which induces inflammatory injury of cerebral tissues; EA treatment can decease the expression of ICAM-1, so as to prevent the brain from the injury.

EFFECTS OF TRANSCRANIAL MAGNETIC STIMULATION ON MOTOR CORTICAL EXCITABILITY AND NEUROFUNCTION AFTER CEREBRAL ISCHEMIA-REPERFUSION INJURY IN RATS

Objective To clarify the effects of repetitive transcranial magnetic stimulation (rTMS) on rat motor cortical excitabi- lity and neurofunction after cerebral ischemia-reperfusion injury. Methods After determined awake resting motor threshold (MT) and motor evoked potentials (MEPs) of right hindlimbs, 20 Sprague-Dawley rats were subjected to middle cerebral artery occlusion (MCAO) reperfusion injury, then rTMS were applied to rTMS group (n = 10) at different time, while control group (n = 10) received no stimulation. A week later, MT and MEPs were evaluated again, as well as neurological deficits and infarct volume. The effects of rTMS and MCAO reperfusion injury on these parameters were analyzed. Results After MCAO reperfusion, both MT level and neurological deficit scores increased, distinct focal infarction formed, and latency of MEP elongated. Compared with the control group, the increased extent of MT and neurological scores of rats receiving rTMS were significantly lower (P < 0.05), as well as the infarct volumes reduced significantly(P < 0.05). But MEP was not affected by rTMS obviously. There was a positive linear correlation between postinjury MT and infarct volume (r = 0.64, P < 0.05). Conclusion rTMS may facilitate neurofunction recovery after cerebral ischemia-reperfusion. Postinjury MT could provide prognostic information after MCAO reperfusion injury.

How to protect liver graft with nitric oxide

Organ preservation and ischemia reperfusion injury associated with liver transplantation play an important role in the induction of graft injury. One of the earliest events associated with the reperfusion injury is endothelial cell dysfunction. It is generally accepted that endothelial nitric oxide synthase （e-NOS） is cell-pro- tective by mediating vasodilatation, whereas inducible nitric oxide synthase mediates liver graft injury after transplantation. We conducted a critical review of the literature evaluating the potential applications of regulating and promoting e-NOS activity in liver preservation and transplantation, showing the most current evidence to support the concept that enhanced bioavailability of NO derived from e-NOS is detrimental to ameliorate graft liver preservation, as well as preventing subse- quent graft reperfusion injury. This review deals mainly with the beneficial effects of promoting ＂endogenous＂ pathways for NO generation, via e-NOS inducer drugs in cold preservation solution, surgical strategies such as ischemic preconditioning, and alternative ＂exogenous＂ pathways that focus on the enrichment of cold storage liquid with NO donors. Finally, we also provide a basic bench-to-bed side summary of the liver physiology and cell signalling mechanisms that account for explaining the e-NOS protective effects in liver preservation and transplantation.

Isoflurane preserves energy balance in isolated hepatocytes during in vitro anoxia/reoxygenation

AIM: To investigate the protective effect of isoflurane on energy balance in isolated hepatocytes during in vitro anoxia/reoxygenation, and to compare isoflurane with halothane. METHODS: Hepatocytes freshly isolated from fed rats were suspended in Krebs-Henseleit buffer, and incubated in sealed flasks under O2/CO2 or N2/CO2 (95%/5%, V/V) for 30 or 60 min, followed by 5 or 10 min of reoxygenation, with an added volatile anesthetic or not. ATP, ADP, and adenosine monophosphate in hepatocytes were determined by high performance liquid chromatography, and energy charge was calculated. RESULTS: During 30 min of anoxia, the energy charge and total adenine nudeotide steadily increased with the isoflurane dose from 0 to 2 minimum alveolar anesthetic concentration (MAC), then decreased from 2 to 3 MAC. In short incubations (30-35 min) at 1 MAC isoflurane, energy charge modestly decreased during anoxia, which was partially prevented by isoflurane and completely reversed by reoxygenation, and total adenine nudeotide did not decrease. In long incubations (60-70 min), both energy charge and total adenine nudeotide greatly decreased during anoxia, with partial and no reversal by reoxygenation, respectively. Isoflurane partly prevented decreases in both energy charge and total adenine nudeotide during anoxia and reoxygenation. In addition, 1 MAC isoflurane obviously increased ATP/ADP, which could not be changed by 1 MAC halothane. CONCLUSION: Isoflurane partially protects isolated hepatocytes against decreases in both energy charge and total adenine nudeotide during short (reversible) or long (irreversible) anoxia.

Gender differences in hepatic ischemic reperfusion injury in rats are associated with endothelial cell nitric oxide synthase-derived nitric oxide

AIM: This study was designed to examine the hypothesis that gender differences in I/R injury are associated withendothelial cell nitric oxide synthase (eNOS)-derived nitric oxide (NO).METHODS: Wistar rats were randomized into seven experimental groups (12 animals per group). Except for the sham operated groups, all rats were subjected to total liver ischemia for 40 min followed by reperfusion. All experimental groups received different treatments 45 min before the laparotomy. For each group, half of the animals (six) were used to investigate the survival; blood samples and liver tissues were obtained in the remaining six animals after 3 h of reperfusion to assess serum NO, alanine aminotransferase (ALT) and TNF-α levels, liver tissuemalondialdehyde (MDA) content, and severity of hepatic I/R injury.RESULTS: Basal serum NO levels in female sham operated (FS) group were nearly 1.5-fold of male sham operated (MS) group (66.7±11.0 μmol/L vs 45.3±10.1μmol/L, P＜0.01). Although serum NO levels decreased significantly after hepatic I/R (P＜0.01, vs sham operated groups), they were still significantly higher in female rat (F) group than in male rat (M) group (47.8±8.6 μmol/L vs 23.8±4.7 μmol/L, P＜0.01). Serum ALT and TNF-α levels, and liver tissue MDA content were significantly lower in F group than in M group (370.5±46.4 U/L, 0.99±0.11 μg/L and 0.57±0.10 μmol/g vs668.7±78.7 U/L, 1.71±0.18 μg/Land 0.86±0.11 μmol/g, respectively, P＜0.01). I/R induced significant injury to the liver both in M and F groups (P＜0.01 vs sham operated groups). But the degree of hepatocyte injury was significantly milder in F group than in M group (P＜0.05 and P＜0.01). The median survival time was six days in F group and one day in M group. The overall survival rate was significantly higher in F group than in M group (P＜0.05). When compared with male rats pretreated with saline (M group), pretreatment of male rats with 17-β- estradiol (E2) (M+E2 group) significantly increased serum NO levels and significantly decreased serum ALT and TNF-α levels, and liver tissue MDA content after I/R (P＜0.01).The degree of hepatocyte injury was significantly decreased and the overall survival rate was significantly improved in M+E2 group than in M group (P＜0.01 and P＜0.05). TheNOS inhibitor Nw-nitro-L-arginine methyl ester (L-NAME) treatment could completely abolish the protective effects of estrogen in both male and female rats. CONCLUSION: The protective effects afforded to female rats subjected to hepatic I/R are associated with eNOSderived NO.

EFFECTS OF INFLAMMATORY CELLS IN COLD AND WARM ISCHEMIA-REPERFUSION INJURY OF THE GRAFTED LIVER

Objective To investigate whether the impairment of grafted livers after transplantation was induced by the same inflammatory cells both in cold and warm ischemia. Methods Male SD rats were divided into two groups at random,24 donor livers in each group were stored in Ringers solution at 4℃ for 120min or 240min of transplantation for blood sample and tissue specimen collection. Results Along with the prolongation of cold and warm ischemia time,the serum ALT,AST and LDH level increased gradually after transplantation.Under light microscopy,some hepatocytes presented necrosis after 3h and 6h of transplantation in cold ischemia,and neutrophilic infiltration in sinusoids were evident.Also,a large number of hepatocytes were necrotic 3h or 6h after transplantation in warm ischemia from NHBDs,and lymphocytic infiltration was evident in the sinusoids.The findings in electron microscopy was as the same as those of light microscopy,and the cells which infiltrated the sinusoids in warm ischemia were identified as T lymphocytes. Conclusion The impairment of grafted livers after transplantation appeared to be induced by two different kinds of inflammatory cells in cold and warm ischemia,that is,neutrophils mediated the cold ischemia-reperfusion,and T lymphocytes mediated the warm ischemia-reperfusion from NHBDs,but these findings are to be comfirmed in further investigations.

Effects of eye-acupuncture on the expression of brainderived neurotrophic factor in the brain of rats with cerebral ischemia reperfusion

Objective To observe the effects of eye-acupuncture therapy and bodyacupuncture therapy on the expression of brain-deprived neurotrophic factor （BDNF） in rats with cerebral ischemia reperfusion injury （CIRI）. Methods According to random number table, 48 SD rats were randomly divided into 6 groups, including normal control group （group A）, sham operation group （group B）, model group （group C）, eye-acupuncture group （group D）, non-acupoint of eye-acupuncture group （group E） and body-acupuncture group （group F）, eight rats in each group. Artery infarction reperfusion model were prepared by using suture-occluded method. Liver region, upper energizer area, lower energizer area and kidney region were selected in the group D. Acupuncture was carried out at the point located at 3 mm from the acupoint areas in the group E. Qūchí （曲池 LI 11）, Zúsānl （足三里 ST 36） and other acupoints were selected in the group F. Zea Longa scoring method was utilized for scoring the neural functions of rats; real-time PCR was carried out to examine the expression level of BDNF mRNA in the brain 72 h after ischemia reperfusion; western blot was carried out to examine the expression level of BDNF protein in the brain 72 h after ischemia reperfusion. Results The symptoms of neurologic impairments in the rats of the group D were alleviated in comparison to those in the group C （P0.01）, and the difference between the group D and the group F was not statistically significant （P0.05）; Compared with the group C, the mRNA and protein expression levels of BDNF in the brain of rats in the group D and the group F both increased （P0.01）, but the difference between the group D and the group F was not statistically significant （P0.05）. Conclusion The functions of eye-acupuncture and body-acupuncture in improving cerebral ischemia reperfusion injury are similar, and the functional mechanisms for the two different therapies may be related to the up-regulation of BDNF expression in brain and thus promote the repairing of brain tissues.

Protection of carbon monoxide-releasing molecule against lung injury induced by limb ischemia-reperfusion

Objective： To observe the role and mechanism of CO- releasing molecule （CORM）-2 in lung injury induced by ischemia-reperfusion （IR） of hind limbs in rats. Methods： Arat model of lung injury induced by IR of hind limbs was established. A total of 40 Sprague Dawley （SD） rats were randomly divided into 5 groups （n = 8）： sham, sham ＋ CORM-2, IR, IR ＋ CORM-2 and IR ＋ dimethyl sulfoxide （DMSO）. Rats in the IR group received hind limb ischemia for 2 hours and reperfusion for 2 hours, rats in the sham group underwent sham surgery without infrarenal aorta occlusion, rats in the IR＋CORM-2 group and in the sham ＋ CORM-2 group were given CORM-2 （10 μmol/kg intravenous bolus） 5 minutes before reperfusion or at the corresponding time points, while rats in the IR ＋ DMSO group was treated with the same dose of vehicle （DMSO） at the same time. The lung tissue structure, polymorphonuclear neutrophil （PMN） count, wet-to-dry weight ratio （W/D）, malondialdehyde （MDA） content, myeloperoxidase （MPO） activity, intercellular adhesion molecule- 1 （ICAM- 1）expression, I κBα degradation and nuclear factor （NF）-κB activity in the lungs were assessed. Results： As compared with the sham group, lung PMNs number, W/D, MDA content, MPO activity, ICAM-1 expression and NF- κB activity significantly increased in the IR group, but the level of I κBα decresed （P〈0.01）. Compared with the IR group, lung PMNs number, W/D, MDA content, MPO activity and ICAM- 1 expression significantly decreased in the IR＋COMR-2 group （P〈0.01）, while the level of IκBα increased. Conclusions： These data demonstrate that CORM-2 attenuates limb IR-induced lung injury through inhibiting ICAM-1 protein expression, NF-κB pathway and the leu- kocytes sequestration in the lungs following limb IR in rats, suggesting that CORM-2 may be used as a therapeutic agent against lung injury induced by limb IR.

Functional recovery of the spinal cord following ischemia and reperfusion injury

Objective: To study the changes of excitatory amino acids (EAAs) and intracellular calcium ([Ca 2+ ]i), and the protective effect of EAAs receptor antagonists in the tissues of rabbit lumbar spinal cord after 40 minues ischemia and 4 hours reperfusion. Methods: Thirty healthy rabbits were divided into six groups: sham operation, 40 minues ischemia,4 hour reperfusion, ketamine and MgSO 4 treatment, ketamine treatment, and saline treatment groups. The contents of EAAs (glutamate and aspartate) and [Ca 2+ ] i were measured. Results: The contents of glutamate and aspartate were decreased to 15.18 μmol/g± 2.33 μmol/g and 9.99 μmol/g ± 0.69 μmol/g, respectively; 13.75 μmol/g± 2.58 μmol/g and 6.49 μmol/g± 1.39 umol/g after reperfusion. In the ischemia group, the [Ca 2+ ]i was elevated to 221.2 μg/g ± 4.27 μg/g, and elevated further to 298.3 μg/g± 9.26 μg/g after reperfusion, being significantly higher than that of ischemia and control groups. Ketamine could obviously increase the level of glutamate and aspartate and decrease the level of [Ca 2+ ]i during the ischemia and reperfusion injury. Conclusions: The excitotoxicity of EAAs and the overload of calcium induced by EAAs play a harmful role in ischemia and reperfusion injury. Ketamine has an effective inhibitory effect.

Effects of electroacupuncture with different frequencies on hippocampal neuronal apoptosis and JNK signaling pathway in rats with vascular dementia

Objective:To observe the effects of electroacupuncture(EA)with three frequencies(100 Hz,2 Hz,and 2 Hz/100 Hz)on the apoptosis of neurons and c-Jun N-terminal kinase(JNK)signaling pathway in the hippocampus of rats with vascular dementia(VD),and explore the mechanism of EA intervention for VD.Methods:Fifty male Sprague-Dawley rats were randomly divided into a model group,a sham operation group,a 100 Hz EA group,a 2 Hz EA group,and a 2 Hz/100 Hz EA group,with ten rats in each group.The VD model rats were established by repeated ischemia-reperfusion of bilateral common carotid arteries.The rats in the EA groups received EA intervention at Baihui(GV20),Dazhui(GV14),Geshu(BL17)and Zusanli(ST36),once a day for 14 d.Afterward,Morris water maze was used to examine the learning and memory performances of the rats in each group,hematoxylin-eosin staining to observe the histomorphological changes in the hippocampal CA1 region,terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling to test the apoptosis of neurons in the hippocampal CA1 region,and Western blot to detect the protein expression levels of JNK,phosphorylated JNK(p-JNK),Caspase-8,and Caspase-3 in the hippocampus tissue.Results:Compared with the sham operation group,the escape latency of the model group in water maze test was prolonged;the number of crossing the original platform was decreased(P<0.01);the hippocampal neurons were severely damaged and the number of surviving neurons was decreased(P<0.01),whereas the number of apoptotic neurons was increased(P<0.01);the protein expression levels of JNK,p-JNK,Caspase-8,and Caspase-3 in the hippocampus were significantly increased(P<0.01).Compared with the model group,the escape latency of each EA group was significantly shortened;the number of crossing the original platform was significantly increased(P<0.01);the damage of hippocampal neurons was alleviated,the number of surviving neurons was increased(P<0.01),and the number of apoptotic neurons was decreased(P<0.01);the protein expression levels of JNK,p-JNK,Caspase-8,and Caspase-3 in the hippocampus were decreased(P<0.01).The results in the 2 Hz EA group and the 2 Hz/100 Hz EA group were superior to those in the 100 Hz EA group.Conclusion:EA with the three frequencies(100 Hz,2 Hz,and 2 Hz/100 Hz)can improve the learning and memory performances in VD rats subjected to ischemia-reperfusion,its mechanism may be related to the inhibition of neuronal apoptosis and the regulation of the related protein expression of JNK signaling pathway,and the intervention effects of EA with 2 Hz and 2 Hz/100 Hz are more significant.

Effects of electroacupuncture of different frequencies on free radicals in hippocampus of mice with vascular dementia

Objective:To observe the effects of electroacupuncture (EA) of three different frequencies (2 Hz,80 Hz and 2 Hz/80 Hz) on the free radicals in hippocampus of vascular dementia (VD) model mice.Methods:A total of 100 Kunming mice were randomly divided into a sham operation group,a model group,a 2 Hz EA group,an 80 Hz EA group and a 2 Hz/80 Hz EA group,with 20 mice in each group.The ischemia-reperfusion VD model was established by repeated blockade of bilateral common carotid arteries.Mice in EA groups began EA treatment on the 4th day after the operation.Baihui (GV 20),Dazhui (GV 14),Geshu (BL 17) and Zusanli (ST 36) were punctured and then connected to EA instrument,with different waves of 2 Hz,80 Hz or 2 Hz/80 Hz (10 min/time) applied accordingly,once a day.During the jumping stand experiment,the learning performance,memory performance and hippocampal calcitonin gene-related peptide (CGRP),nitric oxide synthase (NOS),malondialdehyde (MDA),changes in superoxide dismutase (SOD) and true choline esterase (TChE) were observed.In hippocampus,the CGRP level was determined by radioimmunoassay;the MDA level was determined by thiobarbituric acid colorimetric method;the activities of NOS and TChE were determined by spectrophotometry;the activity of SOD was determined by xanthine oxidase method.Results:Compared with the sham operation group,the performances of learning and memory decreased significantly in the model group (P＜0.01);in hippocampus,the CGRP level decreased,the MDA level increased,the activities of NOS and TChE increased,and the activity of SOD decreased in the model group.Compared with the model group,the learning and memory performances of the EA groups were significantly improved (P＜0.05 or P＜0.01);in hippocampus,the CGRP level increased,the MDA level decreased,the NOS and TChE activities decreased,and the SOD activity increased (P＜0.05 or P＜0.01).Among EA groups,the 2 Hz/80 Hz EA group was superior to the 2 Hz EA group and the 80 Hz EA group (P＜0.05 or P＜0.01).Conclusion:EA can improve the cognitive impairment of mice with ischemia-reperfusion VD.The mechanism may be related to the improvement of cerebral blood circulation,regulation of the central neurotransmitters,fighting lipid peroxidation and promoting nerve cell repair.The therapeutic effects of EA with different frequencies were different,and the intervention effect by EA at 2 Hz/80Hz is the most significant.

Effect of methylprednisolone on reperfusion injury in severe uncontrolled hemorrhagic shock

Objective: To study the effect of methylprednisolone (MP) on reperfusion injury in severe uncontrolled hemorrhagic shock and explore the possible mechanism involved. Methods: Twelve dogs were randomly divided into two groups, control group (Group I, n=6) and MP group (Group II, n=6). The animals were bled continuously from a femoral artery catheter to produce uncontrolled hemorrhagic shock models. Resuscitation with lactated Ringer’s (LR) solution was initiated when mean arterial pressure (MAP) decreased to 20 mm Hg, and MAP was maintained at 30-40 mm Hg. MP (4 mg/kg) was injected intravenously in Group II when resuscitation began. While in Group I, normal saline (NS) was injected instead. The levels of superoxide dismutase (SOD) and malondialdehyde (MDA) were measured before exsanguination (T 1), when MAP decreased to 20 mm Hg (T 2), 60 min (T 3) and 120 min (T 4) after resuscitation. Heart rate, MAP and cardiac output (CO) levels were recorded concomitantly. Results: Infusion volume and hemorrhage volume shed from the superior mesenteric artery in Group I were higher than those in Group II (P< 0.01 and P< 0.05). After reperfusion, blood SOD levels decreased progressively and MDA levels increased rapidly in Group I. In Group II, blood SOD levels at T 3 and T 4 decreased as compared with that at T 1 but a stepwise increase was present. At T 4, blood SOD level was significantly higher in Group II than in Group I (P< 0.01). At T 3 and T 4, MDA levels were markedly lower in Group II than in Group I. During reperfusion, MAP was more steady in Group II than in Group I and survival rate after 120 min (at T 4) was higher in Group II than in Group I (P< 0.05). Conclusions: MP has a protective effect on severe uncontrolled hemorrhagic shock and subsequent reperfusion injury. The mechanism mainly involves the anti-lipid peroxidation activity of MP.