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Alterations in Cardiac Sarcoplasmic Reticulum Ca^<2+> Regulatory proteins in the atrial tissue of patients with chronic atrial fibrilla

山口医学 Volume 50 Issue 4 Page 687-692
published_at 2001-08-31
B030050000401.pdf
[fulltext] 630 KB
Title
慢性心房細動患者の心房筋における筋小胞体Ca^<2+>制御蛋白の変化
Alterations in Cardiac Sarcoplasmic Reticulum Ca^<2+> Regulatory proteins in the atrial tissue of patients with chronic atrial fibrilla
Creators Ohkusa Tomoko
Source Identifiers
Creator Keywords
慢性心房細動 心筋筋小胞体 リアノジンレセプター Ca^<2+>-ATPase
Background Clinically, atrial fibrillation (AF) is the most frequently encountered arrhythmia. Recent studies indicate that an inability to maintain intracellular Ca^<2+> homeostasis with a consequent increase in membrane-triggered activity could be the primary initiating factor in some circumstances, and that cytosolic Ca^<2+> abnormalities are an important mediator of sustained AF. Objectives The purpose of this study was to determine whether AF patients have alterations in the SR Ca^<2+> regulatory proteins in the atrial myocardium. Methods and Results We measured the maximum number of [^3H] ryanodine binding sites (Bmax) and the expression levels of ryanodine receptor (RyR) mRNA and Ca^<2+>-ATPase mRNA in atrial myocardial tissue from 13 patients with AF due to mitral valvular disease (MVD) and 9 patients with normal sinus rhythm (NSR). In AF patients: (i) Bmax was significantly lower in each atrium [0.21±0.03 pmol/mg (right), 0.16±0.04 pmol/mg (left)] than in the right atrium (0.26±0.08 pmol/mg) of NSR patients, (ii) Bmax was significantly lower in the left atrium than in the right atrium, (iii) Bmax in the left atrium was significantly lower at higher levels of pulmonary capillary wedge pressure, (iv) the expression level of RyR mRNA was significantly lower in both the left (1.24x10^<-2>±1.28x10^<-2>) and right (1.70x10^<-2>±1.78x10^<-2>) atrium than in the right atrium of NSR patients (6.11x10^<-2>±2.79x10^<-2>), and (v) the expression level of Ca^<2+>-ATPase mRNA was significantly lower in both the left (5.67x10^<-2>±4.01x10^<-2>) and right (7.71x10^<-2>±3.56x10^<-2>) atrium than in the right atrium (12.60x10^<-2>±3.92x10^<-2>) of NSR patients.Conclusions These results may suggest that, in the patients with chronic AF due to MVD, mechanical overload of the atrial myocardium decreases Bmax for RyRs and the expression of both RyR mRNA and Ca^<2+>-ATPase mRNA. This might result in abnormal intracellular Ca^<2+> handling and alter the electrophysiologic properties of the atrium, leading to the initiation and maintenance of AF.
Subjects
医学 ( Other)
Languages jpn
Resource Type journal article
Publishers 山口大学医学会
Date Issued 2001-08-31
Rights
本文データは山口大学医学会の許諾に基づきCiNiiから複製したものである()
File Version Version of Record
Access Rights open access
Relations
[ISSN]0513-1731
[NCID]AN00243156
[isVersionOf] [NAID]http://ci.nii.ac.jp/naid/110002774120/
Schools 医学部