| Sarcoplasmic reticulum function in murine ventricular myocytes overexpressing SR CaATPase. | |
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MedLine Citation:
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PMID: 9990541 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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To examine the effects of the overexpression of sarcoplasmic reticulum (SR) CaATPase on function of the SR and Ca2+ homeostasis, we measured [Ca2+]i transients (fluo-3), and L-type Ca2+ currents (ICa.L), Na/Ca exchanger currents (INa/Ca), and SR Ca2+ content with voltage clamp in ventricular myocytes isolated from wild type (WT) mice and transgenic (SRTG) mice. The amplitude of [Ca2+]i transients was insignificantly increased in SRTG myocytes, while the diastolic [Ca2+]i tended to be lower. The initial and terminal declines of [Ca2+]i transients were significantly accelerated in SRTG myocytes, implying a functional upregulation of the SR CaATPase. We examined the functional contribution of only the SR CaATPase to the initial and the terminal phase of the decline of [Ca2+]i, by abruptly inhibiting Na/Ca exchange with a rapid switcher device. The rate of [Ca2+] decline mediated by the SR CaATPase was increased by 40% in SRTG compared with WT myocytes. The function of the L-type Ca2+ channel was unchanged in SRTG myocytes, while INa/Ca density was slightly (10%) decreased. Measured SR Ca2+ content was significantly increased by 29% in SRTG myocytes. Thus, overexpression of SR CaATPase markedly accelerates the decline of [Ca2+]i transients, and induces in increase in SR Ca2+ content, with some downregulation of the Na/Ca exchanger. |
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Authors:
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A Yao; Z Su; W H Dillmann; W H Barry |
Publication Detail:
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Type: Journal Article; Research Support, U.S. Gov't, P.H.S. |
Journal Detail:
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Title: Journal of molecular and cellular cardiology Volume: 30 ISSN: 0022-2828 ISO Abbreviation: J. Mol. Cell. Cardiol. Publication Date: 1998 Dec |
Date Detail:
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Created Date: 1999-04-30 Completed Date: 1999-04-30 Revised Date: 2007-11-14 |
Medline Journal Info:
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Nlm Unique ID: 0262322 Medline TA: J Mol Cell Cardiol Country: ENGLAND |
Other Details:
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Languages: eng Pagination: 2711-8 Citation Subset: IM |
Affiliation:
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Division of Cardiology, University of Utah Health Science Center, Salt Lake City 84132, USA. |
Export Citation:
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APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
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Animals Caffeine / pharmacology Calcium / chemistry, physiology Calcium Channels / drug effects, physiology Calcium-Transporting ATPases / physiology* Heart / physiology* Mice Mice, Transgenic Sarcoplasmic Reticulum / physiology* Sodium / physiology Sodium-Calcium Exchanger / drug effects, physiology Time Factors |
| Grant Support | |
ID/Acronym/Agency:
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HL52946/HL/NHLBI NIH HHS; HL53773/HL/NHLBI NIH HHS |
| Chemical | |
Reg. No./Substance:
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0/Calcium Channels; 0/Sodium-Calcium Exchanger; 58-08-2/Caffeine; 7440-23-5/Sodium; 7440-70-2/Calcium; EC 3.6.1.8/Calcium-Transporting ATPases |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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