ABSTRACT
AIM: To investigate the changes of current and gene expression of acetylcholine sensitive K~+ channel (K_ ACh ) in chronic human atrial fibrillation (AF) and to evaluate the roles of K_ ACh expression in the occurring and maintenance of AF. METHODS: Acetylcholine sensitive K~+ currents (I_ KACh ) were recorded with the whole-cell patch clamp technique in single atrial myocyte of AF group and normal sinus rhythm group (SR group). The current densities-voltage relations were analyzed. The Kir3.4 mRNA was measured by reverse transcription-polymerase chain reaction. RESULTS: (1) Compared with SR group, acetylcholine sensitive K~+ current densities in AF group were reduced under testing potential between -80 mV and -120 mV . Acetylcholine sensitive K~+ current density was ( -11.665 ?1.027) pA/pF (n=11) in AF group vs ( -19.486 ?0.766) pA/pF (n=11) in SR group at -100 mV testing potential (P