title: Down-regulated Na(+)/K(+)-ATPase activity in ischemic penumbra after focal cerebral ischemia/reperfusion in rats.
abstract: This study was aimed to examine whether the Na(+)/K(+) adenosine triphosphatase (Na(+)/K(+)-ATPase) activity in ischemic penumbra is associated with the pathogenesis of ischemia/reperfusion-induced brain injury. An experimental model of cerebral ischemia/reperfusion was made by transient middle cerebral artery occlusion (tMCAO) in rats and the changes of Na(+)/K(+)-ATPase activity in the ischemic penumbra was examined by Enzyme Assay Kit. Extensive infarction was observed in the frontal and parietal cortical and subcortical areas at 6 h, 24 h, 48 h, 3 d and 7 d after tMCAO. Enzyme Assay analyses revealed the activity of Na(+)/K(+)-ATPase was decreased in the ischemic penumbra of model rats after focal cerebral ischemia/reperfusion compared with sham-operated rats, and reduced to its minimum at 48 h, while the infarct volume was enlarged gradually. In addition, accompanied by increased brain water content, apoptosis-related bcl-2 and Bax proteins, apoptotic index and neurologic deficits Longa scores, but fluctuated the ratio of bcl-2/Bax. Correlation analysis showed that the infarct volume, apoptotic index, neurologic deficits Longa scores and brain water content were negatively related with Na(+)/K(+)-ATPase activity, while the ratio of bcl-2/Bax was positively related with Na(+)/K(+)-ATPase activity. Our results suggest that down-regulated Na(+)/K(+)-ATPase activity in ischemic penumbra might be involved in the pathogenesis of cerebral ischemia/reperfusion injury presumably through the imbalance ratio of bcl-2/Bax and neuronal apoptosis, and identify novel target for neuroprotective therapeutic intervention in cerebral ischemic disease.
authors.affiliation: Department of Neurology, The Second Affiliated Hospital of Chongqing Medical University Chongqing, China.
authors.forename: Hao
authors.initials: H
authors.lastname: Huang
authors.affiliation: Department of Neurology, The Second Affiliated Hospital of Chongqing Medical University Chongqing, China.
authors.forename: Yang-Mei
authors.initials: YM
authors.lastname: Chen
authors.affiliation: Department of Neurology, People's Hospital of Pingxiang City Pingxiang, Jiangxi Province, China.
authors.forename: Fei
authors.initials: F
authors.lastname: Zhu
authors.affiliation: Department of Neurology, People's Hospital of Guangxi Zhuang Autonomous Region Nanning, China.
authors.forename: Shi-Ting
authors.initials: ST
authors.lastname: Tang
authors.affiliation: Department of Neurology, People's Hospital of Guangxi Zhuang Autonomous Region Nanning, China.
authors.forename: Ji-Dong
authors.initials: JD
authors.lastname: Xiao
authors.affiliation: Department of Neurology, People's Hospital of Guangxi Zhuang Autonomous Region Nanning, China.
authors.forename: Lv-Li
authors.initials: LL
authors.lastname: Li
authors.affiliation: Department of Neurology, People's Hospital of Guangxi Zhuang Autonomous Region Nanning, China.
authors.forename: Xin-Jing
authors.initials: XJ
authors.lastname: Lin
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000502:physiology; D002545:Brain Ischemia / Q000201:enzymology* / Q000473:pathology*; D004195:Disease Models, Animal; D015536:Down-Regulation; D007150:Immunohistochemistry; D020287:In Situ Nick-End Labeling; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D015427:Reperfusion Injury / Q000201:enzymology* / Q000473:pathology*; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism*
chemical_list: D000254:Sodium-Potassium-Exchanging ATPase
keywords: Cerebral ischemia/reperfusion; Na+/K+-ATPase; apoptosis; bax; bcl-2; penumbra