title: Spatio-temporal properties of 5-lipoxygenase expression and activation in the brain after focal cerebral ischemia in rats.
abstract: The role of 5-lipoxygenase (5-LOX) in brain injury after cerebral ischemia has been reported; however, the spatio-temporal properties of 5-LOX expression and the enzymatic activation are unclear. To determine these properties, we observed post-ischemic 5-LOX changes from 3 h to 14 days after reperfusion in rats with transient focal cerebral ischemia induced by 30 min of middle cerebral artery occlusion. We found that the expression of 5-LOX, both mRNA and protein, was increased in the ischemic core 12-24 h after reperfusion, and in the boundary zone adjacent to the ischemic core 7-14 days after reperfusion. The increased 5-LOX was primarily localized in the neurons in the ischemic core at 24 h, but in the proliferated astrocytes in the boundary zone 14 days after reperfusion. As 5-LOX metabolites, the level of cysteinyl-leukotrienes in the ischemic brain was substantially increased 3 h to 24 h, near control at 3 days, and moderately increased again 7 days after reperfusion; whereas the level of LTB(4) was increased mildly 3 h but substantially 7-14 days after reperfusion. Thus, we conclude that 5-LOX expression and the enzymatic activity are increased after focal cerebral ischemia, and spatio-temporally involved in neuron injury in the acute phase and astrocyte proliferation in the late phase.
authors.affiliation: Department of Pharmacology, School of Medicine, Zhejiang University, People's Republic of China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Zhou
authors.forename: Er-Qing
authors.initials: EQ
authors.lastname: Wei
authors.forename: San-Hua
authors.initials: SH
authors.lastname: Fang
authors.forename: Li-Sheng
authors.initials: LS
authors.lastname: Chu
authors.forename: Meng-Ling
authors.initials: ML
authors.lastname: Wang
authors.forename: Wei-Ping
authors.initials: WP
authors.lastname: Zhang
authors.forename: Guo-Liang
authors.initials: GL
authors.lastname: Yu
authors.forename: Yi-Lu
authors.initials: YL
authors.lastname: Ye
authors.forename: Shu-Cai
authors.initials: SC
authors.lastname: Lin
authors.forename: Zhong
authors.initials: Z
authors.lastname: Chen
mesh_terms: D000208:Acute Disease; D000818:Animals; D001094:Arachidonate 5-Lipoxygenase / Q000096:biosynthesis* / Q000235:genetics; D001157:Arterial Occlusive Diseases / Q000378:metabolism; D001253:Astrocytes / Q000201:enzymology / Q000473:pathology; D001921:Brain / Q000201:enzymology* / Q000473:pathology; D049109:Cell Proliferation; D002908:Chronic Disease; D004195:Disease Models, Animal; D004789:Enzyme Activation; D015870:Gene Expression; D007124:Immunoenzyme Techniques; D002546:Ischemic Attack, Transient / Q000201:enzymology* / Q000473:pathology; D015289:Leukotrienes / Q000378:metabolism; D008297:Male; D009474:Neurons / Q000201:enzymology / Q000473:pathology; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D015427:Reperfusion Injury / Q000201:enzymology* / Q000473:pathology; D013997:Time Factors
chemical_list: D015289:Leukotrienes; D012333:RNA, Messenger; D001094:Arachidonate 5-Lipoxygenase