论文部分内容阅读
BACKGROUND:Studies have shown that the Ruhus parvifolius L.(RP)plant extract exhibits protective effects on cerebral ischemia.This effect is reflected in altered ischemic neuronal apoptosis and associated protein expression.OBJECTIVE:To explore the neuroprotective mechanism of RP after cerebral ischemia jniury.DESIGN,TIME AND SETTING:Randomized control experiment of cellular,molecular.and protein levels.The experiment was completed at Chongqing Medical University at the School of Pharmacy Laboratories and Basic Medical Institute from October 2005 to January 2006.MATERIALS:Twenty-four adult,male,Wistar rats,weighing(28±20)g.RP extract,which was a product of ethanol extraction.was provided by the LabOratory of Pharmaceutical Analysis,Chongqing Medical University.RP was dissolved in distilled water to a concentration of 10 mg/mL.All rats were randomly assigned into four groups:5 g/kg RP,10 g/kg RP,model,and sham-surgery,with 6 rats in each group.METHODS:In the 5 and 10 g/kg RP groups,as well as the model group,the middle cerebral artery was occluded(MCAO)for 60 minutes,resulting in focal cerebral ischemia,followed by reperfusion for 24 hours.Rats in the 5 and 10 g/kg RP groups received 5 and 10 g/kg RP,respectively.The RP treatment group received RP intragastrically(once a day)for 3 days.One hour after the last dose,rats were subjected to MCAO.The same surgical procedure was performed in the sham-surgery group,except the suture was introduced into the extemal carotid artery,but not advanced.Rats in the model group were subjected to MCAO.The sham-surgery and model groups received intragastrically administered normal saline once per day for 3 days.One hour after the last dose,the rats were subjected to surgery.MAIN OUTCOME MEASURES:TUNEL labeling and immunohistochemical methods were used to investigate changes in neuronal apoptosis and expression of the apoptosis-related proteins.Bax and Bcl-2.on the ischemic hemisphere,as well as the contralateral hemisphere,after administration of RP or normal saline.RESULTS:All 24 Wistar rats were included in the final analysis.without any loss.Compared with the sham-surgery group,the number of the TUNEL-positive cells in the model group,as well as the 5 and 10 g/kg RP treatment groups,were significantly increased in the ischemic hemisphere(P<0.05).Compared with the sham-surgery group,the number of Bcl-2-positive and Bax-positive cells increased significantly in the model group(P<0.01).The number of Bcl-2-positive cells increased,and the number of Bax-positive cells decreased in the model group,compared to the 5 and 10 g/kg RP treatment groups(P<0.05-0.01).CONCLUSION:RP can prevent neuronal apoptosis following cerebral ischemic-reperfusion of rats.The mechanism underlying the RP-induced neuroprotection in the cerebral ischemia iniury may be related to increased Bcl-2 expression and decreased Bax expression.