title: Na+/Ca2+ exchanger 1 alters in pyramidal cells and expresses in astrocytes of the gerbil hippocampal CA1 region after ischemia.
abstract: Alterations of immunoreactivity and protein contents of Na(+)/Ca(2+) exchanger 1 (NCX1) were observed in the gerbil hippocampus proper after 5 min of transient forebrain ischemia. NCX1 immunoreactivity was significantly changed in the hippocampal CA1 region, but not in the CA2/3 region after ischemia/reperfusion. In the sham-operated group, NCX1 immunoreactivity was mainly detected in CA1 pyramidal cells. However, 30 min after ischemia/reperfusion, NCX1 immunoreactivity was significantly decreased and then increased at 1 day after ischemia. At this time, NCX1 immunoreactivity in CA1 pyramidal cells was similar to that of the sham-operated group. At 3 days after ischemia, NCX1 immunoreactivity was significantly reduced in the CA1 region compared to that of the sham-operated group and NCX1 immunoreactivity was significantly increased again 4 days after ischemia. Thereafter, NCX1 immunoreactivity was decreased time-dependently in ischemia groups. Between 15 min and 6 h post-ischemia, NCX1 immunoreactivity was expressed in astrocytes in the strata oriens and radiatum of the CA1 region. From 3 days post-ischemia, NCX1 immunoreactivity was expressed in astrocytes in the strata oriens and radiatum. Ischemia-induced changes in NCX1 protein contents in the hippocampus proper concurred with immunohistochemical data post-ischemia. Our results suggest that changes in NCX1 in CA1 pyramidal cells and astrocytes after ischemia are associated with intracellular Na(+) concentrations and that NCX1 may induce an intracellular calcium overload, which may be related to neuronal death.
authors.affiliation: Department of Anatomy, College of Medicine, Hallym University, Chunchon 200-702, South Korea.
authors.forename: In Koo
authors.initials: IK
authors.lastname: Hwang
authors.forename: Ki-Yeon
authors.initials: KY
authors.lastname: Yoo
authors.forename: Dae Won
authors.initials: DW
authors.lastname: Kim
authors.forename: Tae-Cheon
authors.initials: TC
authors.lastname: Kang
authors.forename: Soo Young
authors.initials: SY
authors.lastname: Choi
authors.forename: Young-Guen
authors.initials: YG
authors.lastname: Kwon
authors.forename: Byoung Hee
authors.initials: BH
authors.lastname: Han
authors.forename: Jong Sung
authors.initials: JS
authors.lastname: Kim
authors.forename: Moo Ho
authors.initials: MH
authors.lastname: Won
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D000704:Analysis of Variance; D000818:Animals; D001253:Astrocytes / Q000378:metabolism*; D015153:Blotting, Western; D016923:Cell Death; D005786:Gene Expression Regulation / Q000502:physiology*; D005849:Gerbillinae; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism; D006624:Hippocampus / Q000473:pathology*; D007150:Immunohistochemistry / Q000379:methods; D007511:Ischemia / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology; D008297:Male; D017966:Pyramidal Cells / Q000378:metabolism*; D019831:Sodium-Calcium Exchanger / Q000378:metabolism*; D013997:Time Factors
chemical_list: D005904:Glial Fibrillary Acidic Protein; D019831:Sodium-Calcium Exchanger; C110374:sodium-calcium exchanger 1; D000255:Adenosine Triphosphate