ABSTRACT
OBJECTIVE:To study the influence of different doses of naloxone on focal cerebral ischemia reperfusion injury in rats and to explore its mechanism.METHODS:The rats were randomly divided into the sham operation group,the model group,the naloxone group(high dosage,moderate dosage,and low dosage)and the positive control group.The modified Longa method was applied to establish the models of focal cerebral ischemia reperfusion in rats.Infarct size,neurological deficit scores,superoxide dismutase(SOD)activity,malondialdehyde(MDA)content in serum of the model rats were detected.The ultrastructures of the brain tissues were observed by electron microscopy.RESULTS:Ischemia reperfusion injury in model rats resulted in increased neurological deficit scores,larger infarct size,decreased activity of SOD in serum and increased content of MDA.The pathological change and ultrastructural change were evident.The above indices were improved in all the groups administered with different doses of naloxone.CONCLUSIONS:Naloxone has protective effects on rat brain injury caused by focal cerebral ischemia reperfusion,whose mechanism might be related to inhibition of lipid peroxidation.