title: Ryanodine receptor-mediated Ca2+ events in atrial myocytes of patients with atrial fibrillation.
abstract: BACKGROUND
  Many alterations in sarcoplasmic reticulum Ca(2+) handling proteins in atrial myocytes have been associated with atrial fibrillation (AF) in clinical patients, whereas the functional consequences of these alterations mostly remain unclear.
  
  
  RESULTS
  To know whether or not ryanodine receptor (RyR)-mediated intracellular Ca(2+) events in AF atrial myocytes are affected by protein alterations, we investigated spontaneous Ca(2+) sparks and Ca(2+) waves in intact and permeabilized atrial myocytes of AF patients (n(patients) = 21) and normal sinus rhythm (NSR) patients (n(patients) = 22) by laser scanning confocal microscopy. It was found that the frequency, amplitude and rise time of Ca(2+) sparks were comparable between AF and NSR groups, while full width and full duration at half maximum intensity significantly increased in the AF group. Along with these changes, the frequency of small and global Ca(2+) waves increased in AF atrial myocytes.
  
  
  CONCLUSIONS
  Our results clearly indicated that the spatiotemporal properties but not the frequency of Ca(2+) sparks were affected in AF atrial myocytes. In addition, the frequency of Ca(2+) waves increased. This profile of the alterations in RyR-mediated Ca(2+) events in AF atrial myocytes was different from previous studies. The underlying mechanisms, as well as possible reasons for this discrepancy, were discussed.
authors: Bio-X Life Science Research Center, College of Life Science and Biotechnology, Shanghai Jiao Tong University, Shanghai, China.
authors: Xin
authors: X
authors: Liang
authors: Hong
authors: H
authors: Xie
authors: Pei-Hong
authors: PH
authors: Zhu
authors: Jun
authors: J
authors: Hu
authors: Qiang
authors: Q
authors: Zhao
authors: Chun-Sheng
authors: CS
authors: Wang
authors: Cheng
authors: C
authors: Yang
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D001281:Atrial Fibrillation / Q000378:metabolism* / Q000473:pathology; D015220:Calcium Channels / Q000378:metabolism; D020013:Calcium Signaling; D016022:Case-Control Studies; D002478:Cells, Cultured; D005260:Female; D006325:Heart Atria / Q000166:cytology; D006801:Humans; D008297:Male; D008875:Middle Aged; D032383:Myocytes, Cardiac / Q000378:metabolism*; D011336:Probability; D012016:Reference Values; D019837:Ryanodine Receptor Calcium Release Channel / Q000378:metabolism*; D012680:Sensitivity and Specificity
chemical_list: D015220:Calcium Channels; D019837:Ryanodine Receptor Calcium Release Channel