Inhibition of Brain Swelling after Ischemia-Reperfusion by β-Adrenergic Antagonists: Correlation with Increased K+ and Decreased Ca2+ Concentrations in Extracellular Fluid
Joint Authors
Song, Dan
Xu, Junnan
Du, Ting
Yan, Enzhi
Hertz, Leif
Walz, Wolfgang
Peng, Liang
Source
Issue
Vol. 2014, Issue 2014 (31 Dec. 2014), pp.1-10, 10 p.
Publisher
Hindawi Publishing Corporation
Publication Date
2014-11-13
Country of Publication
Egypt
No. of Pages
10
Main Subjects
Abstract EN
Infarct size and brain edema following ischemia/reperfusion are reduced by inhibitors of the Na+, K+, 2Cl−, and water cotransporter NKCC1 and by β 1-adrenoceptor antagonists.
NKCC1 is a secondary active transporter, mainly localized in astrocytes, driven by transmembrane Na+/K+ gradients generated by the Na+,K+-ATPase.
The astrocytic Na+,K+-ATPase is stimulated by small increases in extracellular K+ concentration and by the β-adrenergic agonist isoproterenol.
Larger K+ increases, as occurring during ischemia, also stimulate NKCC1, creating cell swelling.
This study showed no edema after 3 hr medial cerebral artery occlusion but pronounced edema after 8 hr reperfusion.
The edema was abolished by inhibitors of specifically β 1-adrenergic pathways, indicating failure of K+-mediated, but not β 1-adrenoceptor-mediated, stimulation of Na+,K+-ATPase/NKCC1 transport during reoxygenation.
Ninety percent reduction of extracellular Ca2+ concentration occurs in ischemia.
Ca2+ omission abolished K+ uptake in normoxic cultures of astrocytes after addition of 5 mM KCl.
A large decrease in ouabain potency on K+ uptake in cultured astrocytes was also demonstrated in Ca2+-depleted media, and endogenous ouabains are needed for astrocytic K+ uptake.
Thus, among the ionic changes induced by ischemia, the decrease in extracellular Ca2+ causes failure of the high-K+-stimulated Na+,K+-ATPase/NKCC1 ion/water uptake, making β 1-adrenergic activation the only stimulus and its inhibition effective against edema.
American Psychological Association (APA)
Song, Dan& Xu, Junnan& Du, Ting& Yan, Enzhi& Hertz, Leif& Walz, Wolfgang…[et al.]. 2014. Inhibition of Brain Swelling after Ischemia-Reperfusion by β-Adrenergic Antagonists: Correlation with Increased K+ and Decreased Ca2+ Concentrations in Extracellular Fluid. BioMed Research International،Vol. 2014, no. 2014, pp.1-10.
https://search.emarefa.net/detail/BIM-1016618
Modern Language Association (MLA)
Song, Dan…[et al.]. Inhibition of Brain Swelling after Ischemia-Reperfusion by β-Adrenergic Antagonists: Correlation with Increased K+ and Decreased Ca2+ Concentrations in Extracellular Fluid. BioMed Research International No. 2014 (2014), pp.1-10.
https://search.emarefa.net/detail/BIM-1016618
American Medical Association (AMA)
Song, Dan& Xu, Junnan& Du, Ting& Yan, Enzhi& Hertz, Leif& Walz, Wolfgang…[et al.]. Inhibition of Brain Swelling after Ischemia-Reperfusion by β-Adrenergic Antagonists: Correlation with Increased K+ and Decreased Ca2+ Concentrations in Extracellular Fluid. BioMed Research International. 2014. Vol. 2014, no. 2014, pp.1-10.
https://search.emarefa.net/detail/BIM-1016618
Data Type
Journal Articles
Language
English
Notes
Includes bibliographical references
Record ID
BIM-1016618