Expression Of 5-lipoxygenase And Protective Effects Of Zileuton On Focal Cerebral Ischemia-reperfusion Injury

AIM To investigate the expression of 5-lipoxygenase and protective effect of 5-lipoxygenase inhibitor on focal cerebral ischemia reperfusion injury in rats.METHODS The right middle cerebral artery of the rat was occluded by inserting a thread through internal carotid artery for 2 h,and then reperfused for 24 h.Zileuton(10,50 mg?kg-1) was orally administered 2 h before ischemia and 0,5,10 h after reperfusion.The mRNA of 5-LO were detected by RT-PCR;The expression of 5-LO, MMP-9 and AQP4 were measured by IH(P);The extent of neurological deficits was evaluated by Longer'method;The infarction size of brain was measured by TTC staining technique;Morphological changes of brain were observed by HE staining technique;The degree of brain edema was measured by AutoCAD image analysis software;EB was used as labelled compound to detect the permeability of blood-brain barrier(BBB);The content of malondialdehyde(MDA) and nitric oxide(NO),the activities of glutathion peroxidas(eGSH-PX),myeloperoxidas(eMPO)and nitricoxide synthase(NOS) were measured by biochemical method.RESULTS (1) Compared with sham group, the results of IH(P)and RT-PCR proved that the protein and the mRNA of 5-LO both significantly increased in vehicle group.In 10 and 50mg?kg-1 zileuton groups,the protein and the mRNA of 5-LO both decreased especially the large dose;(2)Compared with vehicle group, 10 and 50mg?kg-1 zileuton groups can reduce the neurological score and improve morphological changes of brain,minification the infarct size,inhibit the degree of brain edema and relieve the destroy of BBB,reduce the expression of AQP4 and MMP-9 in nerve cell ,reduce the content of NO and activity of NOS of the brain...