Effects Of Tongxinluo Ultramicro-pulverization And7-Nitroindazole On NO Concentration In Rat Hippocampus With Transient Cerebral Ischemia And Reperfusion

Objective To investigate the efficacy and the mechanism of Tongxinluo ultramicro-pulverization and7-Nitroindazole(7-NI) on nitric oxide (NO) concentration in rat hippocampus after transient cerebral ischemia and reperfusion.Methods The model of cerebral ischemia was made by4-vessel occlusion for10min.Both sides of the rat’s vertebral artery was blocked by galvanocautery under Phenobarbital anaesthesia. The next day,the big rat was fixed on the operation table and their both carotid artery was loosely embosomed by medical silk suture under urethane anaesthesia.The both sides of the silk suture was hanged by5g weigh and was moved after10minutes.The experiment was divided into three groups: Tongxinluo ultramicro-pulverization group(n=5),7-Nitroindazole group(n=4) and normal control (n=8). Saline,Tongxinluo ultramicro-pulverization and7-NI were administered intraperitoneally20min before the onset of ischemial.We measured NO concentration,arterial blood pressure and hippocampal blood flow by an NO-selective electrode method,blood sedimentationunit and the laser Doppler flowmetry.Results We can be observed three groups of NO concentration,arterial blood pressure and the hippocampal blood flow without obvious difference before cerebral ischemia(P>0.05).The hippocampal blood flow decreased in the cerebral ischemic process,but NO concentration,the hippocampal blood flow also did not differ significantly in three groups.Both Tongxinluo and7-NI compared with saline group,Tongxinluo and7-NI significantly reduced the NO production during post-ischemic early reperfusion(P<0.001). Conclusion Tongxinluo ultramicro-pulverization and7-Nitroindazole have protective effect on hippocampal neurons against cerebral ischemia reperfusion injury by reducing the activity of neuronal NO synthase (nNOS) or reducing the content of NO in hippocampus of rat.