ObjectiveTo investigate the protective effect and the regulation mechanism of oxaloacetate (OAA) on myocardial ischemia reperfusion injury in rats. MethodsSixty rats, weight ranged from 200 to 250 grams, were randomly divided into 6 groups:a negative control group, a sham operation control group, a model control group, an OAA pretreatment myocardial ischemia-reperfusion model group (three subgroups:15 mg/kg, 60 mg/kg, 240 mg/kg). We established the model of myocardial ischemia reperfusion of rats and recorded the internal pressure of left ventricle (LVSP), the maximal rate of left ventricular pressure change (±dp/dtmax) and left ventricular end diastolic pressure (LVEDP). We restored reperfusion 180 minutes after ligating the left anterior descending coronary artery 30 minutes and determinated cardiac troponin Ⅰ (cTn-I), lactate dehydrogenase (LDH), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px). We took out heart tissues, stained it and calculated the infarcted size. We used the Western blot to detect the expression of NF-E2 related factor 2 (Nrf2), Kelch-like ECH-associated protein-1 (Keap1) and heme oxygenase-1 (HO-1). ResultsCompared with the sham operation group, heart function indexes in the negative control group had no significant difference (P>0.05). But in the model control group there was a decrease (P<0.05) And the serum levels of LDH, cTn-I, and myocardial infarcted size were significantly increased (P<0.01). Compared with the model control group, heart function indexes in the OAA pretreatment groups improved, the serum LDH, cTn-I activity, and infarct size decreased (P<0.05), SOD and GSH-Px activity increased (P<0.05). And these results were statistically different (P<0.01) in the high dose OAA pretreatment groups. Compared with the model control group, the expression of Keap1 in the OAA pretreatment group was down-regulated (P<0.001) while total Nrf2, nucleus Nrf2 and its downstream HO-1 was up-regulated (P<0.001), which suggested that OAA enhanced antioxidant capacity by (at least in part) Keap1-Nrf2 pathway, resulting in reducing myocardial damage and protecting myocardium after acute myocardial ischemia reperfusion injury. ConclusionOxaloacetate can provide protective effects on myocardial ischemia reperfusion injury through down-regulating the expression of Keap1 and up-regulating the expression of Nrf2 and its downstream peroxiredoxins to improve antioxidant capacity.
Objective To study the protective effects of pre-storing glycogen on warm ischemia reperfusion injury during partial hepatectomy. Methods Thirty-eight patients were randomly divided into a trial group (n=19) and a control group (n=19). In the trial group, patients were given high concentration glucose intravenously during the 24 hours before the operation. The hepatic lesion was resected after portal triad clamping in the two groups. Liver function of all patients was measured before the operation and the first and fifth days after the operation. Normal hepatic tissue was biopsied to measured hepatic tissue glycogen contents before the operation and the change of superoxide dismutase (SOD) at the point of pre-ischemia, post-ischemia, and reperfusion 2 hour. Bcl-2 mRNA, a well known anti-apoptotic factor, was also detected using quantitative polymerase chain reaction. Results The hepatic tissue glycogen content of the trial group was significantly higher than that of the control group before the operation (Plt;0.01). Liver function of the trial group was significantly better than that of the control group on the first and fifth day after operation (Plt;0.05). There was significant difference in SOD activity between the two groups at the end of hepatic vascular occlusion and at the point of 2-hour reperfusion (Plt;0.05). Furthermore Bcl-2 mRNA expression of the trial group was notably up-regulated at the point of 2-hour reperfusion compared to the control group. Conclusion Pre-store storing glycogen might protect liver ischemia reperfusion injury caused by hepatic vascular occlusion during partial hepatectomy. The potential mechanism might be that pre-storing glycogen enhances Bcl-2 expression.
【摘要】 目的 探讨抗氧化应激是否参与参附注射液预处理诱导的肾脏保护作用。 方法 健康成年雄性SD大鼠21只随机分为假手术对照组（Sham组）、肾脏缺血再灌注组（I/R组）和参附注射液组（SF组）；SF组给予参附注射液10 mL/kg腹腔注射，每日1次，连续给药7d。麻醉下行右肾切除后，用无损伤动脉夹钳夹左侧肾蒂60min，再灌注24 h，制备肾缺血再灌注损伤动物模型。比较各组SD大鼠再灌注24 h肾脏组织中超氧化物歧化酶（superonidedismutase，SOD）水平、过氧化氢酶（catalese，CAT）和丙二醛（malonicalaldehyed，MDA）含量。 结果 与Sham组相比，I/R和SF组肾脏组织SOD和CAT显著降低，而MDA明显升高（Plt;0.05）；与I/R组比，参附注射液能明显增加SOD和CAT水平（Plt;0.05），降低MDA含量（Plt;0.05）。 结论 参附注射液预处理可增强缺血再灌注损伤肾脏组织抗氧化应激，其表现为增强SOD和CAT的活力，减少MDA的生成。【Abstract】 Objective To explore the protective effect of Shenfu injection combined with antioxidant system on rats’ kidney after ischemia-reperfusion injury. Methods Twenty-one male Sprague Dawley (SD) rats were randomly divided into 3 groups: sham operation group (Sham group), ischemia-reperfusion group (IR group), and shenfu injection treated group (SF group). The rats were anesthetized with valebarbitone. Bilateral kidneys were exposed through midline incision. The right kidney underwent the nephrectomy and left renal pedicels were occluded for 60 minutes with a traumatic mini-clamp and then unclamped for 24 hours. Animals in SF group received Shenfu injection (10 mL/kg) through intraperitoneal injection every day for 7 days. About 24 hours after reperfusion, superoxide dismutase (SOD), CAT and malonical aldehyde (MDA) were measured. Results The levels of MDA were lower in SF group than those in IR group (Plt;0.05). The level of SOD and CAT in SF group increased more significantly than which did in IR group (Plt;0.05). Conclusion Our finding suggests that antioxidant system in SF group works more efficiently than IR group to overcome oxidative stress in renal ischemia-reperfusion injury.
Objective To explore repair role of allogeneic bone marrow mesenchymal stem cells （BM-MSCs） transplantation on treating hepatic ischemia reperfusion injury （HIRI） in rats. Methods Ten rats were executed to get BM-MSCs， then BM-MSCs were cultured in vitro and dyed by 4，6-diamidino-2-phenylindole （DAPI）. Models of 70% hepatic ischemia reperfusion injury were eatablished. Thirty two rats were randomly divided into sham operation group （Sham group）， ischemia reperfusion group （I/R group）， Vitamin C group （VC group）， and BM-MSCs group. Serum samples were analyzed for ALT and AST， and hepatic tissue were for superoxide dismutase （SOD） and malondialdehyde （MDA）. Liver sections were stain with hematoxylin and eosin （HE） for histological analysis， TUNEL staining was applied to detect hepatic apoptosis. Serum and tissues were both collected at 24 h after reperfusion. Results The isolated BM-MSCs maintained vigorous growth in vitro. Specific markers for MSCs antigens CD29 and CD44 were detected by flow cytometry， but antigens CD34 and CD45 were not be detected. Models of HIRI were stable， and BM-MSCs were detected around the periportal area by DAPI staining. Compared with I/R group， levels of ALT， AST， MDA， and AI in the VC group and BM-MSCs group decreased at 24 h after reperfusion （P＜0.05）， meanwhile SOD level increased （P＜0.05）. Compared with VC group， levels of ALT， AST， MDA， and AI in the BM-MSC group decreased at 24 h after reperfusion （P＜0.05）， meanwhile SOD level increased （P＜0.05）. Conclusion BM-MSCs could protect HIRI by alleviating oxidative stress and inhibiting cellular apoptosis.
ObjectiveTo investigate the protective mechanism of prostaglandin E1 against hepatic ischemia reperfusion injury.MethodsUsing 45minute ischemiareperfusion rat model in normal temperature, PGE1 was injected into portal vein before ischemia. An hour later blood was taken from portal vein to examine the enzyme levels, including GOT, GPT, LDH and TNFα, ET1. The alteration of pathological morphology of the ischemia lobe was observed.ResultsThe three enzemes, TNFα, ET1 levels of ischemiareperfusion group were significantly higher than those of the control group (P＜0.01). The indices of the PGE1 group were much lower than those of the ischemiareperfusion group (P＜0.01), but little higher than those of the control group (P＞0.05). The control group had obvious alteration in pathological morphology, but only slight alteration in PGE1 group, compared with the control group. ConclusionPGE1 protects against ischemiareperfusion injury of the liver.
ObjectiveTo investigate the protective effects of glycine on rat sinusoidal endothelial cells (SECs) after hepatic warm ischemiareperfusion and its mechanism.MethodsSeventytwo male SD rats were randomly divided into the normal control,ischemiareperfusion,glycine plus strychnine treated and glycine treated groups. The changes of endothelin (ET),hyaluronic acid (HA),tumor necrosis factorα (TNFα) content and alanine aminotransterase (ALT), superoxide dismutase (SOD) activity as well as morphology of SECs under light microscope were observed at the time point 1,3,24 h after hepatic reperfusion. The effects of glycine on the above parameters were also observed. ResultsThe group using glycine treated, the abnormal changes of all above parameters were improved remarkably (P＜0.01 or P＜0.05). Strychnine can antagonize these effects partly.ConclusionGlycine can prevent the injury to rat SECs after hepatic warm ischemiareperfusion.It most likely acts through glycine receptor on SECs and Kupffer cells.
Objective To investigate the protective effect of ischemic preconditioning (IP) on ischemicreperfusion injury of rat liver graft. MethodsMale Sprague Dawley rats were used as donors and recipients of orthotopic liver transplantation,the period of cold preservation and anhepatic phase were 100 min and 25 min respectively.Sixtyfour rats were randomly divided into 2 groups (n=32),control group: donor livers were flushed through the portal veins with physiological saline solution containing heparin only before harvested; IP group: before donor livers were harvested,the portal veins and hepatic arteries of them were interrupted for 10 min,and reflow was initiated for another 10 min,then did as control group.One half of each group were used to investigate 1 week survival rate of recipients,and another half of each group were used to take sample of blood and hepatic tissue after 2 hours of reperfusion of liver graft. ResultsOne week survival rate,amount of bile,serum NO and activity of antioxidase were higher in IP group than those in control group(P＜0.05),meanwhile,serum ALT,AST,LDH,TNF and superoxide in hepatic tissue were lower in IP group than those in control group (P＜0.05),and histological findings in IP group showed less injury than those in control group. Conclusion IP could increase production of serum NO,reduce the level of serum TNF and protect rat liver graft from ischemicreperfusion injury.
Objective To establish a new model on isolated human cadaver testes with ischemiareperfusion (I/R). MethodsThirteen isolated cadaver testes contributed by 13 persons were preserved under 0℃-4℃ hypothermia and then reperfused under 37℃. Histological and histochemical changes were observed. Results4℃ cold ischemia in 12 hours induced only trivial swelling and vascular degeneration of endothelial cells (ECs), obvious pathologic changes occurred after 24 hours, including detachment of ECs, separation between basement membrane and seminiferous epithelium, degeneration and detachment of spermatogenous cell and edema of mesenchyme. Injury was worse along with the prolongation of cold preservation time. Changes of LDH and SDH activities were found by histochemical staining. Reperfusion following 6 hours ischemia induced tissue injury and unusual enzyme activity. All changes were more obvious after reperfusion following 12,18,24 or 36 hours cold ischemia.Conclusion This new model on isolated cadaver testes with ischemiareperfusion is successful, it can substitute other solid organs of human beings for I/R injury study.
Objective To study the effect of Kupffer cell on the liver ischemia/reperfusion injury.Methods The literature in recent years on the liver ischemia/reperfusin injury were reviewed.Results The activated kupffer cell can generate and release a variety of soluble toxic mediators, affect the liver microcirculation directly or indirectly. Conclusion Kupffer cell have important effect on liver ischemia/reperfusion injury.