title: Na+/HCO3- cotransporter immunoreactivity changes in neurons and expresses in astrocytes in the gerbil hippocampal CA1 region after ischemia/reperfusion.
abstract: The maintenance of intracellular pH is important in neuronal function. Na(+)/HCO(3)(-) cotransporter (NBC), a bicarbonate-dependent acid-base transport protein, may contribute to cellular acid-base homeostasis in pathophysiological processes. We examined the alterations of NBC immunoreactivity and its protein levels in the hippocampal CA1 region after transient cerebral ischemia in gerbils. In the sham-operated group, moderate NBC immunoreactivity was detected in CA1 pyramidal neurons, and, 12 h after I/R, the immunoreactivity in the pyramidal neurons was markedly increased over controls. Three days after I/R, NBC immunoreactivity nearly disappeared in the CA1 pyramidal neurons. However, NBC immunoreactivity was detected in the non-pyramidal neurons of the ischemic CA1 region at 3 days after I/R. From double immunofluorescence study with glial markers, NBC immunoreactivity was detected in astrocytes, not in microglia, at 4 days after I/R. NBC protein level in the CA1 region was significantly increased at 12 h post-ischemia and significantly decreased at 2 days post-ischemia. Thereafter, NBC protein level was again increased and returned to the level of the sham-operated group at 4 days post-ischemia. On the other hand, treatment with 4,4'-diisothiocyanatostilbene-2,2'-disulfonate (DIDS), an inorganic anion exchanger blocker including Cl-bicarbonate exchanger, protected CA1 pyramidal neurons from I/R injury at 4 days post-ischemia. These results indicate that changes in NBC expressions may play an important role in neuronal damage and astrocytosis induced by transient cerebral ischemia.
authors.affiliation: Department of Emergency Medicine, and Institute of Medical Sciences, Kangwon National University Hospital, School of Medicine, Kangwon National University, Chuncheon 200-701, South Korea.
authors.forename: Youdong
authors.initials: Y
authors.lastname: Sohn
authors.forename: Ki-Yeon
authors.initials: KY
authors.lastname: Yoo
authors.forename: Ok Kyu
authors.initials: OK
authors.lastname: Park
authors.forename: Seung-Hae
authors.initials: SH
authors.lastname: Kwon
authors.forename: Choong Hyun
authors.initials: CH
authors.lastname: Lee
authors.forename: Jung Hoon
authors.initials: JH
authors.lastname: Choi
authors.forename: In Koo
authors.initials: IK
authors.lastname: Hwang
authors.forename: Jeong Yeol
authors.initials: JY
authors.lastname: Seo
authors.forename: Jun Hwi
authors.initials: JH
authors.lastname: Cho
authors.forename: Moo-Ho
authors.initials: MH
authors.lastname: Won
mesh_terms: D017878:4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid / Q000494:pharmacology; D000818:Animals; D001253:Astrocytes / Q000378:metabolism; D056547:CA1 Region, Hippocampal / Q000378:metabolism* / Q000473:pathology; D005849:Gerbillinae; D002546:Ischemic Attack, Transient / Q000503:physiopathology; D008297:Male; D009474:Neurons / Q000276:immunology / Q000378:metabolism; D015427:Reperfusion Injury / Q000276:immunology / Q000378:metabolism*; D027982:Sodium-Bicarbonate Symporters / Q000096:biosynthesis / Q000276:immunology*
chemical_list: D027982:Sodium-Bicarbonate Symporters; D017878:4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid