ObjectiveTo study the changes of levels of α subunits of stimulatory (Gsα) and inhibitory guanine nucleotide binding protein (Giα) in newborn guinea pig (0 2 days old) myocardium undergoing global ischemic reperfusion, and influences on the changes by St.Thomas Ⅱ and cold blood cardioplegic solution.MethodsThirty newborn guinea pigs were randomly assigned to three groups. GroupⅠ ( n = 10): the newborn hearts suffered by hypothermic global ischemia; group Ⅱ( n =10): the newborn hearts arrested by St. Thomas Ⅱ , and group Ⅲ ( n = 10): the newborn hearts arrested by cold blood cardioplegic solution. Levels of Gsα and Giα were investigated with Western blot analysis.ResultsNo differences of levels of Gsα and Giα were found in three groups before ischemia ( P gt;0.05). The level of Gsα after ischemia was significantly decreased than before ischemia in groupⅠand group Ⅱ ( P lt; 0 01), whereas no pronounced changes in group Ⅲ ( P gt;0.05) were noted after ischemia. The level of Gsα in group Ⅲ was not significantly changed after reperfusion compared with before ischemia( P gt;0 05), and it was much higher than those in groupⅠand group Ⅱ ( P lt; 0 01). Level of Giα was found not markedly changed in group Ⅲ after reperfusion compared with that before ischemia, but was notable higher in groupⅠand group Ⅱ( P lt;0.01). ConclusionsSignificant decrease of level of Gsα, whereas marked increase of level of Giα are found in myocardium of newborn guinea pig undergoing hypothermic (20℃) ischemic reperfusion. No impact of St. Thomas Ⅱ on these changes is verified, but recovery to the level of Gsα and Giα before ischemia is achieved by cold blood cardioplegic solution after ischemia and reperfusion. Unbalance between Gsα and Giα is the one of the mechanisms of ischemic reperfusion injury for immature myocardium.
rough the ultramicroscopic observation on muscle and microcirculation, Group A,where a largeamount of DXM combined with heporin was given svstematically and locally into the femoral artery of the severed limb before replantation, and in Group B only heporin was given, and Group C and D ascontrol.The results showed that if the hormone and heparin were administred in large dosage, it wasadvantageous to reduce the tissues from reperfusion injury during delayed replantation.
Objective To study the efect of IH764-3 on ischemia-reperfusion (I/R) injury in rat liver. Methods Rats were divided into 3 groups, the control group was not subjected to ischemia and no treatment was given. I/R injury group was subjected to 40 minutes ischemia followed by reperfusion for 120 minutes. The IH7643 group (40mg/kg) was administred at ischemia and reperfusion. Results In the IH764-3 group, sereum levels of ALT, AST, AKP and γ-GT were significantly lower than those in the I/R group. Energy charge level recovery was significantly higher with IH7643 (P＜0.05), hepatic ultrastructure was better preserved with IH764-3. Conclusion IH764-3 may be useful in the treatment of hepatic ischemia reperfusion injury
【Abstract】 Objective To study the effects of ischemic preconditioning (IP) on the activity of nuclear factor-κB （NF-κB） and the expressions of TNF-α and intercellular adhesion molecule-1 (ICAM-1) during early reperfusion following liver transplantation in rats. Methods The models of rat orthotopic liver transplantation were established. The donor livers were stored for 2 hours in Ringers solution at 4 ℃ before transplantation. All rats were randomly divided into sham operation group （SO group）， control group and IP group. IP group was achieved by clamping the portal vein and hepatic artery of donor liver for 10 minutes followed by reperfusion for 10 minutes before harvesting. The activity of NF-κB and expressions of TNF-α and ICAM-1 at 1 h, 2 h, 4 h and 6 h after reperfusion were measured. Serum ALT, LDH were also determined. Results The liver function of recipients with IP were significantly improved. Compared with SO group， the graft NF-κB activity increased after transplantation in control group and IP group (P＜0.05), while compared with control group that was significantly attenuated at 1 h and 2 h in IP group. Similarly, hepatic levels of TNF-α and ICAM-1 were significantly elevated in control group and were reduced in IP group. Conclusion IP might down-regulated TNF-α and ICAM-1 expression in the grafts after orthotopic liver transplantation through depressed NF-κB activation， and attenuate neutrophil infiltration in the grafts after reperfusion.
Objective To investigate the effects of different reperfusion sequence on hepatic warm ischemia-reperfusion injury and its related mechanisms. Methods Ninety-six healthy male Sprague Dawley rats were randomly divided into 6 groups by using random digits method (n=16, each)： Sham operation group, only shammed operation for negative control; the other 5 groups were all experimental groups, which were divided according to different reperfusion sequences of portal vein and hepatic artery: reperfusion first through the portal vein for 1 min with subsequent full reperfusion group, reperfusion first through the portal vein for 2 min with subsequent full reperfusion group, reperfusion first through the hepatic artery for 1 min with subsequent full reperfusion group, reperfusion first through the hepatic artery for 2 min with subsequent full reperfusion group, simultaneous reperfusion through the portal vein and hepatic artery group. Each group was further randomly divided into two subgroups (n=8, each) for sample collection at 2, 4 hours after reperfusion respectively. Serum alanine aminotransferase (ALT), aspartate aminotransferase (AST) and malondialdehyde (MDA), superoxide dismutase (SOD) and glutathion (GSH) in hepatic tissue were detected respectively. HE staining of histopathologic slides was used to observe the morphological changes of hepatic tissue. TUNEL method was used to assess the apoptosis index (AI) of hepatocytes. Results The liver of rat was approximately normal in the sham operation group with lower levels of ALT, AST, MDA and AI, and higher levels of SOD and GSH as compared with all the experimental groups (P＜0.01). Less hepatic ischemia-reperfusion injury was found in reperfusion first through the portal vein for 1 min with subsequent full reperfusion group, whose ALT, AST, MDA and AI levels were significantly lower than those of the other experimental groups (P＜0.05 or P＜0.01), and its SOD and GSH levels were higher than those of the other experimental groups (P＜0.05 or P＜0.01). HE staining also showed milder hepatic injury in reperfusion first through the portal vein for 1 min with subsequent full reperfusion group as compared with the other experimental groups. Conclusion Hepatic reperfusion first through portal vein for short time with subsequent full reperfusion could depress the synthesis of free oxygen radicals and suppress apoptosis of hepatocytes, thus relieving hepatic ischemia-reperfusion injury.
ObjectiveTo summarize recent researches on mechanism of the hepatic ischemic preconditioning (IPC) and its clinical applications on hepatectomy and liver transplantation. MethodsRelevant references about basic and clinical researches of hepatic IPC were collected and reviewed. ResultsRecent experimental researches indicated that IPC could relieve hepatic ischemiareperfusion injury (IRI) by remaining and improving energy metabolism of liver, regulating microcirculation disorder, decreasing the production of lipid peroxidation and oxyradical. It could also inhibit the activation of inflammatory cells and the release of cytokine, suppress cell apoptosis and induce the release of endogenous protective substance. Till now, most of the clinical researches had confirmed the protective function of hepatic IPC, but there were still some references with opposite opinions. ConclusionHepatic IPC could relieve liver IRI, but its clinical application value on hepatectomy and liver transplantation still need more researches to prove.
ObjectiveTo explore performances of functional magnetic resonance imaging (MRI) in evaluation of hepatic warm ischemia-reperfusion injury.MethodThe relative references about the principle of functional MRI and its application in the assessment of hepatic warm ischemia-reperfusion injury were reviewed and summarized.ResultsThe main functional MRI techniques for the assessment of hepatic warm ischemia-reperfusion injury included the diffusion weighted imaging (DWI), intravoxel incoherent motion (IVIM), diffusion tensor imaging (DTI), blood oxygen level dependent (BOLD), dynamic contrast enhancement MRI (DCE-MRI), and T2 mapping, etc.. These techniques mainly used in the animal model with hepatic warm ischemia-reperfusion injury currently.ConclusionsFrom current results of researches of animal models, functional MRI is a non-invasive tool to accurately and quantitatively evaluate microscopic information changes of liver tissue in vivo. It can provide a useful information on further understanding of mechanism and prognosis of hepatic warm ischemia-reperfusion injury. With development of donation after cardiac death, functional MRI will play a more important role in evaluation of hepatic warm ischemia-reperfusion injury.
Objective To investigate the expressions of heat shock protein 27 (HSP27), Bcl-2, and Bax proteins of the nerve cells after spinal cord ischemia/reperfusion injury (SCII) in rats and their relationship. Methods Seventy adult male Sprague Dawley rats (weighing, 200-220 g) were randomly divided into the sham operated group (sham group, n=35) and the SCII group (n=35). Only the left renal artery was exposed with no occlusion of the abdominal aorta in the rats of sham group. The left renal artery was exposed with occlusion of the abdominal aorta for 20 minutes in the rats of SCII group. At 4, 8, and 12 hours and at 1, 2, 3, and 5 days, reperfusion treatment was performed in 5 rats respectively, and then the spinal cord tissue was harvested to detect the expressions of HSP27, Bcl-2, and Bax protein of the nerve cells by using immunohistochemistry staining. Results The HSP27 began to express at 4 hours, reached the peak at 3 days, and decreased at 5 days in SCII group; significant differences were found between at 3 and 5 days and at the other time points (P lt; 0.05). The Bcl-2 expression increased at 4 hours, reached the peak at 1 day and maintained a high level at 2 days, and then gradually decreased; significant differences were found between at 1 and 2 days and at the other time points (P lt; 0.05). The Bax expression reached the peak at 12 hours and 3 days, and decreased at 5 days; significant differences were found between at 12 hours and 3 days and at the other time points (P lt; 0.05). A little expression of each protein was observed in sham group at different time points; the expressions of HSP27, Bcl-2, and Bax proteins in SCII group were significantly higher than those in sham group at different time points (P lt; 0.05). Conclusion There may be the time window of self repair after SCII. High expression of HSP27 has an obvious protective effect on the SCII in rat, by promoting the expression of the anti-apoptotic protein Bcl-2 and reducing the expression of the pro-apoptotic protein Bax so as to inhibit spinal cord cell apoptosis.