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 systematically evaluate the influence of alcohol intervention on the outcome of rats and mice with ischemic stroke. Methods Databases including PubMed, EMbase, BIOSIS and CNKI were electronically searched from establishment dates of databases to June 2012 to retrieve animal experiments on the influence of alcohol intervention on the outcome of rats and mice with ischemic stroke. The relevant studies were identified according to the predefined inclusion and exclusion criteria, the data were extracted, and the quality was evaluated. Then meta-analysis was performed using RevMan 5.1 software. Results Eight studies were included. The results of meta-analysis showed that no significant difference was found between the alcohol intervention group and the control group (MD=−6.98%, 95%CI −20.38% to 6.43%, P=0.31). However, compared with the control group, low dose of acute alcohol intervention (less than 2 g/kg) improved the prognosis of ischemic stroke with a significant difference (MD=−22.83%, 95%CI −38.77% to −6.89%, P=0.005), and highly-concentrated of chronic alcohol intervention worsened the cerebral ischemic damage of rats and mice with a significant difference (MD=24.06%, 95%CI 10.54% to 37.58%, P=0.000 5). Conclusion Low dose of acute alcohol intervention (less than 2 g/kg) could improve the prognosis of rats and mice with ischemic stroke which has the potential neuro-protective effects. However, highly-concentrated chronic alcohol intervention could worsen the cerebral ischemic damage. Due to the limitations of the included studies such as publication bias, the influence of alcohol intervention on the outcome of rats and mice with ischemic stroke could be overestimated.
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.
Objective To establish chronic hindlimb ischemia model with suture-occluded method in rats， and then compare the effects of chronic hindlimb ischemia model with acute ischemia model. Methods Models of chronic hindlimb ischemia were established by using suture-occluded femoral artery method. The laser Doppler blood flow analysis and angiography were performed on day 7， 14， 28， 42， and 49 after operation， and then the rats were sacrificed after angiography， respectively， the quadriceps and gastrocnemius of contralateral and ipsilateral （surgical side） were gotten， which were tested by HE staining and α-actin immunohistochemistry staining， and then calculate arteriolar density. Results There were no lameness and limb necrosis after operation in chronic hindlimb ischemia models. Laser Doppler analysis found that chronic hindlimb ischemia models were still maintained in ischemia state on day 49 after operation compared with acute ischemic models. The resluts of HE staining showed no acute necrosis and muscle fibrosis in chronic hindlimb ischemia model group. Chronic hindlimb ischemia models after operation did not appear obvious lameness and limb necrosis. The arteriolar density of quadriceps femoris on day 7 after operation in chronic hindlimb ischemia models were less than that in acute hindlimb ischemia models （0.015 2 vs. 0.036 4）. Conclusions Compared with the commonly used acute ischemic models， the duration of arterial limb ischemia in chronic hindlimb ischemia rats， which were established by suture-occluded method， is longer and less likely to be affected by the compensatory mechanisms. So suture-occluded method can provide a new animal hindlimb ischemia model for further study of ischemia angiogenesis mechanism and treatment of severe lower extremity ischemia.
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.
Objective To investigate the extent of hepatic ischemia reperfusion (HIR) injury in rat cirrhotic liver under different ischemic time，and find the time limit under which the rat with cirrhotic liver could tolerate. Methods At first，the cirrhosis of the rat were induced by carbon tetrachloride（CCl4）injected subcutaneously. Then these rats were randomly divided into four groups. Group A(n=6) was made by sham operation, group B, C, D(n=16) were respectively given 20, 30, 40min hepatic warm ischemia. The 7day survival rate, AST, ALT, TNF and liver, pulmonary pathology were observed. Results The 7-day survival rate was decreased with the increase of hepatic ischemic time. The survival rate of group B, C, D were respectively 100%, 60%, 40%. Between group C, D and group B there were significant differences（P＜0.05）. The level of AST and ALT in group D were （2 448.4±942.3）u/L and （1 189.0±403.4）u/L respectively, and those in group C were （2 185.1±1 732.9）u/L and （1 183.5±707.2）u/L respectively, which were higher than those in group B and A significantly（P＜0.01）. The level of TNF was increased significantly 4hr after reperfusion, as compared with that before operation 〔(0.177±0.139）u/ml〕, P＜0.01. TNF of group B, C, D were （0.399±0.216）u/ml, （0.671±0.351）u/ml and （0.789±0.371）u/ml respectively. At the same time the level of TNF in group C, D was higher than that in group B, A significantly（P＜0.01）. Liver and lung pathology showed increased damage with increasing ischemia. Conclusion Hepatic injury is induced by HIR in rats with cirrhotic liver, and its severity increases with the increase of ischemic time. There is a certain hepatic ischemic time between 20min and 30min, which can be tolerated by the rats with cirrhotic liver. TNF may be used as an indicator，showing the degree of HIR injury and foreseeing the result of injury.
【Abstract】Objective To investigate the protective effect of improving the pancreatic ischemia and calcium channel blockers on preventing the progression of acute pancreatitis. Methods Twenty-four patients with mild acute pancreatitis were randomly divided into two groups： control group and treated group. Within the first 72 hours from the onset of AP, routine conservative managements were performed in control group, improving the pancreatic ischemia and preventing Ca2+ overload were performed in treated group for two weeks. The hemorrheological parameters were measured at 1,4,7,14 days after adimission, simultanously, serum TNFα, IL-1β, C-reactive protein and plasma TXB2, 6-keto-PGF1α levels were determined with ELISA methods. Results The hemorrheological changes were improved in treated group, serum TNFα, IL-1β, C-reactive protein and plasma TXB2, 6-keto-PGF1α levels were significantly decreased each time point in treated group as compared with control group. Conclusion Improving the pancreatic ischemia and calcium channel blockers have protective effect through reducing the generation of cytokines and inflammatory mediators on preventing the progression of acute pancreatitis.
The aim of this study is to assess ischemia/reperfusion injury in carbon tetrachloride induced cirrhotic liver as compared to normal liver in the rats. Results showed that in cirrhotic liver, instead of diminishing the hepatic vein nitric oxide level increased significantly after ischemia from 8.04 μmol/L to 11.52 μmol/L and remained high till 5 hrs after reperfusion. The hepatic adenosine triphosphate (ATP) contents decreased as that seen in normal rat but did not restore to normal till the end of 5 hrs after reperfusion. Based on these findings, it is postulated that in cirrhotic liver, ischemia/reperfusion injury is aggrvated as evidenced by of nitric oxide, and extended diminishing in ATP.
A simple model of canine auto-trasplantation of liver was set up by ourselves, and the effects of hepatic artery ischemia (HAI) on ultrastructure of liver and biliary duct transplanted were observed. The results showed that the liver and biliary cells swelled slightly, mitochondrial matrix was loose and ridges were vague just often perfusion. Afte HAI for 3 hours the edema of hepatic and biliary cells aggravated cytoplasm was loose, mitochondria enlarged and partly vacuolar degenerated, ridges broke or disappeared, flocculent focal densites was seen in the matrix, endoplasmic retculum distended obviously, and the ribosome depolymerizated. So we consider that HAI causes obvious damage to hepatic and biliary cells. These indicate that HAI is one of the important factors of complication after liver transplantation, especially some biliary complications.
Abstract： Objective To investigate the effects of hepatocyte growth factor（HGF）gene transfected bone marrow mesenchymal stem cells （MSCs）transplantation in pigs with chronic ischemic heart disease. Methods MSCs were isolated from pig bone marrow by density gradient centrifugation and adherent cell culture, purified, and determined by cellsurface antigens（CD34, CD44, CD71, Ⅷ factor and desmin）. MSCs were transfected by adenovirus expressing hepatocyte growth factor（AdHGF）, and the influence of HGF on the biological characteristics of MSCs was tested. The pig model of chronic myocardial ischemia was established by placing Ameroid ring inside the left circumflex coronary artery via leftthoracotomy. A total of 40 pigs were randomly divided into 5 groups （n=8） and were injected 5×106/ml MSCs＋ 4×109 pfu 200 μl AdHGF （MSCs＋ AdHGF group）, 4×109 pfu 200 μl AdHGF （AdHGF group）, 5×106/ml MSCs 200 μl（MSCs group），4×109 pfu 200 μl AdNull （AdNull group）and 1 ml saline（control group） into the ischemic myocardiumrespectively. Echocardiogram, digital subtraction angiography （DSA） of coronary artery, single photon emission computed tomography（SPECT） myocardial perfusion imaging and cardiomyocyte apoptosis were examined after 4 weeks. Results Positive CD44 and CD71 and negative CD34, Ⅷ factorand desmin were detected in MSCs by flow cytometer. HGF had a b influence on stimulating the proliferation and differentiation of MSCs. Echocardiogram examination showed that left ventricular end-diastolic volume（LVEDV），left ventricular ejection fraction（LVEF），fractional shortening（FS）of MSCs＋ AdHGF group were significantly increased after treatment （P＜ 0.05）. DSA detection showed that ischemic neovascularization of MSCs＋ AdHGF group was significantly higher than those of AdHGF group and MSCs group （P＜ 0.05）. SPECT showed that the left ventricular myocardium of MSCs＋ AdHGF group appeared thickened,myocardial perfusion was significantly improved and the myocardial motion was significantly increased （P＜ 0.05）. Vascular density of MSCs＋ AdHGF group was significantly higher than those of AdHGF group and MSCs group by HE stain of myocardium ［（39.4±1.2）/ HPF vs. （36.5±1.4）/ HPF and（34.5±1.7）/ HPF，P＜ 0.05］. Cardiomyocyte apoptosis rate of MSCs＋ AdHGF group was significantly lower than those of AdHGF group and MSCs group by TUNEL stain （P＜ 0.05）. Conclusion Combination transplantation can promote the angiogenesis of chronic ischemic myocardium, inhibit cardiomyocyte apoptosis and improve heart function in pigs with chronic ischemic heart disease. The effect of HGF gene transfected MSCs transplantation is better than that of MSCs or HGF transplantation alone.