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Title: The H{sub 1}–H{sub 2} domain of the α{sub 1} isoform of Na{sup +}–K{sup +}–ATPase is involved in ouabain toxicity in rat ventricular myocytes

Abstract

The composition of different isoforms of Na{sup +}-K{sup +}-ATPase (NKA, Na/K pump) in ventricular myocytes is an important factor in determining the therapeutic effect and toxicity of cardiac glycosides (CGs) on heart failure. The mechanism whereby CGs cause these effects is still not completely clear. In the present study, we prepared two site-specific antibodies (SSA78 and WJS) against the H{sub 1}–H{sub 2} domain of α{sub 1} and α{sub 2} isoforms of NKA in rat heart, respectively, and compared their influences on the effect of ouabain (OUA) in isolated rat ventricular myocytes. SSA78 or WJS, which can specifically bind with the α{sub 1} or α{sub 2} isoform, were assessed with enzyme linked immunosorbent assay (ELISA), Western blot and immunofluorescent staining methods. Preincubation of myocytes with SSA78 inhibited low OUA affinity pump current but not high OUA affinity pump current, reduced the rise in cytosolic calcium concentration ([Ca{sup 2+}]{sub i}), attenuated mitochondrial Ca{sup 2+} overload, restored mitochondrial membrane potential reduction, and delayed the decrease of the myocardial contractile force as well as the occurrence of arrhythmic contraction induced by high concentrations (1 mM) but not low concentrations (1 μM) of OUA. Similarly, preincubation of myocytes with WJS inhibited high OUA affinity pumpmore » current, reduced the increase of [Ca{sup 2+}]{sub i} and the contractility induced by 1 μM but not that induced by 1 mM OUA. These results indicate that the H{sub 1}–H{sub 2} domain of the NKA α{sub 1} isoform mediates OUA-induced cardiac toxicity in rat ventricular myocytes, and inhibitors for this binding site may be used as an adjunct to CGs treatment for cardiovascular disease. -- Highlights: ► We prepared two antibodies against the H{sub 1}-H{sub 2} domain of α{sub 1} and α{sub 2} isoforms of NKA. ► The H{sub 1}-H{sub 2} domain of the NKA α{sub 1} isoform mediates OUA-induced cardiac toxicity. ► The H{sub 1}-H{sub 2} domain of the NKA α{sub 2} isoform mediates OUA-induced positive inotropic.« less

Authors:
; ; ; ; ; ;
Publication Date:
OSTI Identifier:
22215345
Resource Type:
Journal Article
Journal Name:
Toxicology and Applied Pharmacology
Additional Journal Information:
Journal Volume: 262; Journal Issue: 1; Other Information: Copyright (c) 2012 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0041-008X
Country of Publication:
United States
Language:
English
Subject:
60 APPLIED LIFE SCIENCES; ANTIBODIES; CALCIUM; CALCIUM IONS; CARDIOVASCULAR DISEASES; CONCENTRATION RATIO; ENZYME IMMUNOASSAY; ENZYMES; HEART; HEART FAILURE; MITOCHONDRIA; OUABAIN; POTASSIUM IONS; RATS; SODIUM IONS; TOXICITY

Citation Formats

Xiong, Chen, Li, Jun-xia, Guo, Hui-cai, Zhang, Li-nan, Guo, Wei, Meng, Jing, and Wang, Yong-li, E-mail: wangyongli@gmail.com. The H{sub 1}–H{sub 2} domain of the α{sub 1} isoform of Na{sup +}–K{sup +}–ATPase is involved in ouabain toxicity in rat ventricular myocytes. United States: N. p., 2012. Web. doi:10.1016/J.TAAP.2012.04.016.
Xiong, Chen, Li, Jun-xia, Guo, Hui-cai, Zhang, Li-nan, Guo, Wei, Meng, Jing, & Wang, Yong-li, E-mail: wangyongli@gmail.com. The H{sub 1}–H{sub 2} domain of the α{sub 1} isoform of Na{sup +}–K{sup +}–ATPase is involved in ouabain toxicity in rat ventricular myocytes. United States. doi:10.1016/J.TAAP.2012.04.016.
Xiong, Chen, Li, Jun-xia, Guo, Hui-cai, Zhang, Li-nan, Guo, Wei, Meng, Jing, and Wang, Yong-li, E-mail: wangyongli@gmail.com. Sun . "The H{sub 1}–H{sub 2} domain of the α{sub 1} isoform of Na{sup +}–K{sup +}–ATPase is involved in ouabain toxicity in rat ventricular myocytes". United States. doi:10.1016/J.TAAP.2012.04.016.
@article{osti_22215345,
title = {The H{sub 1}–H{sub 2} domain of the α{sub 1} isoform of Na{sup +}–K{sup +}–ATPase is involved in ouabain toxicity in rat ventricular myocytes},
author = {Xiong, Chen and Li, Jun-xia and Guo, Hui-cai and Zhang, Li-nan and Guo, Wei and Meng, Jing and Wang, Yong-li, E-mail: wangyongli@gmail.com},
abstractNote = {The composition of different isoforms of Na{sup +}-K{sup +}-ATPase (NKA, Na/K pump) in ventricular myocytes is an important factor in determining the therapeutic effect and toxicity of cardiac glycosides (CGs) on heart failure. The mechanism whereby CGs cause these effects is still not completely clear. In the present study, we prepared two site-specific antibodies (SSA78 and WJS) against the H{sub 1}–H{sub 2} domain of α{sub 1} and α{sub 2} isoforms of NKA in rat heart, respectively, and compared their influences on the effect of ouabain (OUA) in isolated rat ventricular myocytes. SSA78 or WJS, which can specifically bind with the α{sub 1} or α{sub 2} isoform, were assessed with enzyme linked immunosorbent assay (ELISA), Western blot and immunofluorescent staining methods. Preincubation of myocytes with SSA78 inhibited low OUA affinity pump current but not high OUA affinity pump current, reduced the rise in cytosolic calcium concentration ([Ca{sup 2+}]{sub i}), attenuated mitochondrial Ca{sup 2+} overload, restored mitochondrial membrane potential reduction, and delayed the decrease of the myocardial contractile force as well as the occurrence of arrhythmic contraction induced by high concentrations (1 mM) but not low concentrations (1 μM) of OUA. Similarly, preincubation of myocytes with WJS inhibited high OUA affinity pump current, reduced the increase of [Ca{sup 2+}]{sub i} and the contractility induced by 1 μM but not that induced by 1 mM OUA. These results indicate that the H{sub 1}–H{sub 2} domain of the NKA α{sub 1} isoform mediates OUA-induced cardiac toxicity in rat ventricular myocytes, and inhibitors for this binding site may be used as an adjunct to CGs treatment for cardiovascular disease. -- Highlights: ► We prepared two antibodies against the H{sub 1}-H{sub 2} domain of α{sub 1} and α{sub 2} isoforms of NKA. ► The H{sub 1}-H{sub 2} domain of the NKA α{sub 1} isoform mediates OUA-induced cardiac toxicity. ► The H{sub 1}-H{sub 2} domain of the NKA α{sub 2} isoform mediates OUA-induced positive inotropic.},
doi = {10.1016/J.TAAP.2012.04.016},
journal = {Toxicology and Applied Pharmacology},
issn = {0041-008X},
number = 1,
volume = 262,
place = {United States},
year = {2012},
month = {7}
}