title: [Human inward rectifying potassium current and Kir2.1 mRNA expression in myocytes isolated from patients with chronic atrial fibrillation].
abstract: OBJECTIVE
  To compare the changes of both inward rectifying K(+) (Kir) current(I(k1)) density and mRNA expression level of Kir2.1, a major subfamily of Kir in chronic human atrial fibrillation (CAF) with those in normal sinus rhythm (NSR).
  
  
  METHODS
  I(k1) density was measured with whole-cell patch clamp technique in single myocyte isolated by an enzymatic dissociation method from right atrial appendages in patients with CAF (n = 8) and those with NSR (n = 12). The mRNA expression levels of Kir2.1 was determined in right atrial appendages from CAF (n = 19) and NSR (n = 18) by semiquantitative reverse-transcription polymerase chain reaction (RT-PCR).
  
  
  RESULTS
  The average resting membrane potentials were similar between CAF and NSR (-78.95 mV +/- 4.67 mV and -70.22 mV +/- 11.08 mV, P>0.05). I(k1) density in single myocyte significantly increased at hyperpolarized potential level (-100 mV) in CAF compared to that in NSR (-9.59 pA/pF +/- 2.47 pA/pF vs. -5.58 pA/pF +/- 2.52 pA/pF, P<0.01). The mRNA level of Kir2.1 was also significantly higher in CAF than that of NSR (0.50+/-0.16 vs. 0.34+/-0.09, P<0.05).
  
  
  CONCLUSIONS
  The data suggest that Kir2.1 up-regulation and I(k1) current increase might contribute to the electrical remodeling in CAF patients.
authors.affiliation: Institute of Myocardium Electrophysiology, Luzhou Medical College, Luzhou 646000, Sichuan, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Zhang
authors.forename: Xiao-rong
authors.initials: XR
authors.lastname: Zeng
authors.forename: Yan
authors.initials: Y
authors.lastname: Yang
authors.forename: Biao
authors.initials: B
authors.lastname: Zhang
authors.forename: Zhi-fei
authors.initials: ZF
authors.lastname: Liu
authors.forename: Miao-ling
authors.initials: ML
authors.lastname: Li
authors.forename: Wen
authors.initials: W
authors.lastname: Zhou
authors.forename: Jie
authors.initials: J
authors.lastname: Pei
mesh_terms: D001281:Atrial Fibrillation / Q000235:genetics / Q000378:metabolism* / Q000503:physiopathology; D015870:Gene Expression; D006801:Humans; D032383:Myocytes, Cardiac / Q000378:metabolism* / Q000502:physiology; D018408:Patch-Clamp Techniques; D024661:Potassium Channels, Inwardly Rectifying / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics
chemical_list: C489457:KCNJ2 protein, human; D024661:Potassium Channels, Inwardly Rectifying; D012333:RNA, Messenger