Abstract: AIM: To investigate alterations in gene expression of chloride channel ClC-3 in patients with atrial fibrillation (AF). METHODS: Right atrial appendages specimen were obtained from 33 patients with chronic AF(CAF group), 7 with paroxysmal AF(PAF group) and 31 matched controls in sinus rhythm (SR group) who underwent open-heart surgery. In this study, the semi-quantitative polymerase chain reaction (RT-PCR) was used to examine the mRNA expression of ClC-3 channel in atrial tissue. RESULTS: The content of ClC-3 mRNA in CAF group was higher than that in SR group(P <0.01), and it was correlated with AF duration (r =0.376, P = 0.001). There was no significant difference in the gene expression of ClC-3 between PAF group and SR group, although the content of ClC-3 mRNA was slightly higher than that in SR group (P >0.05). CONCLUSION: The increased gene expression of chloride channel ClC-3 may be served as the molecular basis of I_Cl.VOL remodeling in patients with atrial fibrillation (AF).

Key words: atrial fibrillation, chloride channel, RT-PCR, gene expression