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Objective To explore the impact and significance of hypoxia preconditioning on the expression of cytochrome C and caspase 3 protein in rats after hepatic resection.Methods A hepatectomy model was used to study the ischemia reperfusion injury in hepatic resection.Sprague-Dawley rats were randomly divided into the following three groups:normal control (NC) group,hepatic resection(HR) group,and hypoxia preconditioning (HP) group,there were twenty four rats in each group.HP Group was given an 10％ oxygen-mixed gas for 90 minutes before the operation.At 1,6,12 and 24 hours after the operation,the rats were killed and the following tests were conducted:(1) Liver tissue was sampled to observe the expression of cytochrome C and caspase 3 protein; (2) blood was drawn to conduct a chemical examination; (3) Liver tissue and morphology was observed by transmission electron microscopy.Results The serum levels of ALT and AST in HP group were significantly lower than that of HR group (P＜0.05) at 1,6,12 and 24 hours after the hepatic resection.In each time,liver function of the HP group was significantly better than the HR group; The expression of cytochrome C and caspase 3 protein was decreased significantly in HP group at each measurement point.Hepatic cells in HR group showed typical apoptosis signs under transmission electron microscopy (TEM),but no apoptosis was found in HP group.Conclusion HP has marked inhibition to apoptosis by down-regulating the expression of Cyt C and Caspase-3protein and protection to chondrosomes after a hepatic resection.
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Objective To investigate the effects of PPTA on auditory brainstem responses (ABR) and the change of co-chlear histomorphology in guinea pig cochlea with ischemia/reperfusion injury .Methods The ischemia/reperfusion model was made by blocking bilateral vertebral artery and the right common carotid artery .Thirty -two healthy guinea pigs were used in this study ,they were divided into four groups randomly ,8 animals/group ,the normal control group(group I ,no treatment group) ,blank control group (group II ,guinea pig were only dissected of the bilateral vertebral artery ,bilateral common carotid artery without occlusion of the artery ) ,and ischemia/reperfusion control group(group III ,equal dose of normal saline were given by intravenous injection to the successful ischemia/reperfusion model through femoral vein) ,ischemia/reperfusion group treated with PPTA (group IV ,PPTA ,10 mg/kg ,were given by intravenous injection to the successful ischemia/reperfusion model) . Ischemia/reperfusion treated with PPTA group injected PPTA via femoral vein after reperfusion immediately ,ischemia/reper-fusion control group inject same dose of normal saline .Thresholds of ABR were measured before and after every experiment . The cochlea were taken quickly when 24h after reperfusion ,four guinea pigs in each group were assigned to Scanning Electron Microscope(SEM) randomly ,while others were assigned to Transmission Electron Microscope (TEM) to observe the change of histomorphology of cochlear .Results Before ischemia ,the ABR threshold of the four groups had no differences .At 24h of ischemia/reperfusion ,the ABR thresholds in group III and group IV were significantly higher than those of in group I and group II(P<0 .05);the threshold of group IV was significantly lower than that of group III (P<0 .05) .Morphological results showed that the cilia of outer hair cell of ischemia reperfusion control group were lodging and scaling ,the cilia of the inner hair cell were scattered ,the nucleus of vascular endothelial cell were pycnosis and margination ,the neurons were demyelinating . Application of PPTA decreased the cochlear structure damage after ischemia/reperfusion .Conclusion Intravenous application of PPTA in the early period of cochlear with ischemia/reperfusion can protect hearing and decrease the damage of cochlea in g uinea pig s .
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Objective To investigate the effects of taurine on the expression of stem cell factor mRNA of the focal cerebral ischemia in rat.Methods 63 adult male rats were randomly divided into taurine-treated group (Taurine, 80 mg/kg, began at the day of MCAO and continuously intravenous injection for 10 min, daily for 7 days) and controlled group (0.9% normal saline, 1 ml, continuously intravenous injection for 10 min daily for 7 days). The rats received right middle cerebral artery occlusion at 2h and different hours of reperfusion. Expression of SCF was detected by in situ hybridization in the rats subjected to2h,24h,3d,7d, 14 d of reperfusion and sham-operated group (n=3). Results Low level SCF mRNA expressions were found in cortex, striatum and extraventricular zone in sham-operated group. The expression of SCF mRNA in ischemic hemisphere of controlled group increased markedly compared with sham-operated group (t=2.16~25.19, P＜ 0.05), besides that of 2 h in cortex, 2 h in striatum, 2h and 14d in extraventricular zone. SCF mRNA expression in the treatment group increased markedly in cortex,striatum and extraventricular zone at 3d and 7d(t=5.19~ 26.17,P＜0.05). Conclusion Taurine increased the SCF mRNA expression in MCAO rats, therefore it might promote the creation of neural stem cell.
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Aim To study the protective effects of Xinnaoshenkang (XNSK) against focal cerebral injury caused by ischmia-reperfusion in rats and its mechanism. Methods The focal brain ischmia-reperfusion model in rats was made through by using an intraluminal monofilament to occlude the middle cerebral artery for 1.5 h and then reperfusing for 24h.Spectrophotometric assay was used to measure the contents of malondial-dehyde (MDA), lactic acid (LA),superoxide dismutase(SOD), reactive oxygen species(ROS), nitricoxide synthase(NOS) and several ATPase in cerebral cortex homogenates from rats. The effects on platelet aggregation were also observed. Results Compared with model and positive control groups,88,175,350 mg?kg-1 XNSK groups were found having significant inhibition of cerebral infarction,MDA,LA,ROS,NOS,platelet aggregation and significant increase of the activity of SOD,ATPase. Conclusion XNSK has protective effects against focal cerebral injury caused by ischmia-reperfusion in rats.
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AIM To study the protective effects of ( ) epigallocatechin 3 gallate (EGCG) against renal ischmia reperfusion injury. METHODS The renal ischemia reperfusion injury model in rat was made by means of ligating bilateral renal arteries for 60 min and then reperfusion. 10 mg?kg -1 and 40 mg?kg -1 EGCG were given by intravenation before and after operation respectively. Spectrophotometric assay were used to measure the contents of serum creatinine(Scr), blood urea nitrogen (Bun) in serum and the activity of superoxide dismutase (SOD) and Ca 2+ ATPase ,the contents of malondialdehyde (MDA), reactive oxygen species (ROS) in renal hemogenate from rats. Renal pathologic changes were also observed. RESULTS Compared with model control group , 40 mg?kg -1 EGCG group was found of significant inhibition in changes of Scr, Bun,MDA,ROS and significant increases in activity of SOD and Ca 2+ ATPase.The renal morphological injury of EGCG groups were slighter than that of model control group. CONCLUSION EGCG has protective effects aganist renal ischemia reperefusion injury via its antioxidant activity and intracellular caclcium reduction.