Please use this identifier to cite or link to this item:
Type: Artigo de periódico
Title: Myocardial Remodeling after Large Infarcts in Rat Converts Post Rest-Potentiation in Force Decay
Author: Bocalini, Danilo Sales
dos-Santos, Leonardo
Antonio, Ednei Luiz
dos Santos, Alexandra Alberta
Davel, Ana Paula
Rossoni, Luciana Venturini
Vassallo, Dalton Valentim
Ferreira Tucci, Paulo Jose
Abstract: Background: Post-rest contraction (PRC) of cardiac muscle provides indirect information about the intracellular calcium handling. Objective: Our aim was to study the behavior of PRC, and its underlying mechanisms, in rats with myocardial infarction. Methods: Six weeks after coronary occlusion, the contractility of papillary muscles (PM) obtained from sham-operated (C, n = 17), moderate infarcted (MMI, n = 10) and large infarcted (LMI, n = 14) rats was evaluated, following rest intervals of 10 to 60 seconds before and after incubation with lithium chloride (Li+) substituting sodium chloride or ryanodine (Ry). Protein expression of SR Ca(2+)-ATPase (SERCA2), Na+/Ca2+ exchanger (NCX), phospholamban (PLB) and phospho-Ser(16)-PLB were analyzed by Western blotting. Results: MMI exhibited reduced PRC potentiation when compared to C. Opposing the normal potentiation for C, post-rest decays of force were observed in LMI muscles. In addition, Ry blocked PRC decay or potentiation observed in LMI and C; Li+ inhibited NCX and converted PRC decay to potentiation in LMI. Although MMI and LMI presented decreased SERCA2 (72 +/- 7% and 47 +/- 9% of Control, respectively) and phospho-Ser(16)-PLB (75 +/- 5% and 46 +/- 11%, respectively) protein expression, overexpression of NCX (175 +/- 20%) was only observed in LMI muscles. Conclusion: Our results showed, for the first time ever, that myocardial remodeling after MI in rats may change the regular potentiation to post-rest decay by affecting myocyte Ca(2+) handling proteins. (Arq Bras Cardiol 2012;98(3):243-251)
Subject: Ventricular remodeling
myocardial infarction
muscle relaxation
muscle strength
Country: Brazil
Editor: Arquivos Brasileiros Cardiologia
Rights: fechado
Date Issue: 2012
Appears in Collections:IB - Artigos e Outros Documentos

Files in This Item:
File Description SizeFormat 
WOS000303198300011_I.pdfversão inglês476.44 kBAdobe PDFView/Open
WOS000303198300011_P.pdfversão português527.45 kBAdobe PDFView/Open
WOS000303198300011_E.pdfversão espanhol480.55 kBAdobe PDFView/Open

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.