[Human inward rectifying potassium current in myocytes isolated from patients with rheumatic atrial fibrillation].
OBJECTIVE
To compare the changes of inward rectifying K(+) (Kir) current (I(K1)) density in atrial myocytes of patients with rheumatic atrial fibrillation (RAF) less or longer than 6 months.


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 RAF less than 6 months (n = 18) and longer than 6 months (n = 18), RAF patients with normal sinus rhythm (NSR, n = 18) served as control.


RESULTS
The average resting membrane potentials were similar between various groups. I(K1) density in single myocyte at -50 to -100 mV of patients with RAF longer than 6 months was significantly increased compared to that in patients with RAF less than 6 months and NSR patients. I(K1) density in single myocyte at hyperpolarized potential level (-100 mV) was also significantly increased in patients with RAF longer than 6 months (8.94 +/- 0.15) than that in patients with RAF less than 6 months (4.35 +/- 0.49) and NSR patients compared to that in NSR (4.05 +/- 0.96, P < 0.05 vs RAF longer than 6 months).


CONCLUSIONS
The data suggest I(K1) current increase might contribute to the electrical remodeling in RAF patients.
Zhang
Biao
B
Department of Physiology, Guangdong Medical College, Zhanjiang 524023, China.
Tong
Lin
L
Zeng
Xiao-rong
XR
Yang
Yan
Y
Liu
Zhi-fei
ZF
D000328:Adult; D001281:Atrial Fibrillation / Q000378:metabolism* / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D032383:Myocytes, Cardiac / Q000378:metabolism*; D018408:Patch-Clamp Techniques; D011188:Potassium / Q000378:metabolism; D024661:Potassium Channels, Inwardly Rectifying / Q000378:metabolism*
D024661:Potassium Channels, Inwardly Rectifying; D011188:Potassium