[Study on expression of mineralocorticoid receptor in human atria during atrial fibrillation].
OBJECTIVE
To investigate the mRNA and protein expression of mineralocorticoid receptor (MR) in patients with atrial fibrillation.


METHODS
Twenty-five patients with rheumatic heart valve disease, 12 in sinus rhythm and 13 in chronic atrial fibrillation (>or= 6 months), underwent transthoracic echocardiography and right and left atrial lateral wall tissue samples were obtained from these patients during mitral/aortic valve replacement operation. Realtime quantitative PCR and Western blot were used to determine the mRNA and protein expression of MR in atria specimens. The distribution of MR in human atria was analyzed by specific immunohistochemical staining.


RESULTS
The left atrial diameters increased markedly in atrial fibrillation group compared with that in sinus rhythm group (P<0.01). And the results showed that the level of mRNA and protein of MR were increased significantly in atrial fibrillation group compared with those in sinus rhythm group (P<0.01 or 0.05), whereas the expression of mRNA and protein of MR were found to be no difference between left atria and right atria both in fibrillation and sinus groups (all P>0.05). The special immunohistochemical staining demonstrated that MR was abundant in the human atrial myocardium and MRs were located mainly in the cytoplasm of atrial cells, which were more evident in atrial fibrillation group than those in sinus rhythm group.


CONCLUSIONS
These findings suggested that MRs were upregulated in atrial fibrillation and aldosterone antagonists may be effective in treating atrial fibrillation.
Pei
De-an
DA
Department of Cardiothoracic Surgery, Changhai Hospital, Secondary Military Medical University, Shanghai 200433, China.
Li
Li
L
Xu
Zhi-yun
ZY
Zou
Liang-jian
LJ
Zhang
Bao-ren
BR
Huang
Sheng-dong
SD
Hao
Jia-hua
JH
Wang
Zhi-nong
ZN
Lu
Fang-lin
FL
D000328:Adult; D001281:Atrial Fibrillation / Q000378:metabolism*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009206:Myocardium / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics; D018161:Receptors, Mineralocorticoid / Q000378:metabolism*
D012333:RNA, Messenger; D018161:Receptors, Mineralocorticoid