Protective Effects And Mechanisms Of PNS On Focal Cerebral Ischemia-Reperfusion Injury In Rats

OBJECTIVE The aims of this study are to investigate the protective effects and its possible mechanisms of PNS on the brain after ischemia-reperfusion injury in rats using the model of reversible middle cerebral artery occlusion(MCAO).METHODS Protective effects:60 healthy male Wistar rats were randomly divided into 6 groups: group I (sham), anesthesia and vessel separation only; group II (IR), ischemia-reperfusion and same volume of NS intravenously (iv) ; groups III, ischemia-reperfusion and nimodipine 0.4mg ? kg^-1 iv. groups IV-VI, ischemia-reperfusion and PNS(30mg ? kg^-1,60mg ? kg^-1, 120mg ? kg^-1) iv respectively. Rats were prepared for models of focal brain ischemic injury by inserting a 0.25-0.30mm 0D nylon thread into middle cerebral artery to make it occluded. One hour later, the thread was withdrown to resume perfusion. Drugs were administered at the beginning of ischemic injury and resume perfusion after 1 hour's ischemic injury. Twenty-four hours after reperfusion, rats were sacrificed by heads cutting and brains removing for the following studies: Ten rats in each group were used to estimate the volume of brain ischemic damage.