title: Effects of acetylcholine on electrical remodeling of human atrial fibers.
abstract: Autonomic nervous system activation can result in significant changes of atrial electrophysiology and facilitate induction of atrial fibrillation. By recording influence of different concentrations of acetylcholine (ACh) on atrial fibers (AF), we investigated the role of the increased vagal tone in electrical remodeling in atrial fibrillation. Parameters of action potentials and force contraction (Fc) in atrial fibers were recorded by using standard intracellular microelectrode technique and force transducer. It was found that: (1) ACh at 0.1 μmol/L had no significant influence on spontaneous action potentials (SAPs) and Fc (n=6, P>0.05); ACh at both 1.0 and 10.0 μmol/L shortened action potential duration (APD) and Fc of human AF from right atrium (n=6, P<0.05); there was no significant difference in shortening APD between 10.0 and 1.0 μmol/L of ACh; (2) ACh at 0.1 μmol/L had no significant desensitization (n=6, P>0.05), but ACh at 1.0 and 10.0 μmol/L had desensitization (n=6, P<0.05) to SAPs and Fc. The desensitization of ACh on APD in AF was concentration- and time-dependent. It was shown that APD was longer than the control along with extending time of continuous Tyrode's solution perfusion after desensitization. It is concluded that ACh changes the electrophysiological characteristics of human AF, indicating that increased vagal tone plays a role in the development of a vulnerable substrate for atrial electrical remodeling in atrial fibrillation.
authors.affiliation: Department of Cardiovascular Surgery, Huazhong University of Science and Technology, Wuhan, 430022, China.
authors.forename: Chengkun
authors.initials: C
authors.lastname: Xia
authors.affiliation: Department of Cardiovascular Surgery, Huazhong University of Science and Technology, Wuhan, 430022, China. xjh_kyc@hotmail.com.
authors.forename: Jiahong
authors.initials: J
authors.lastname: Xia
authors.affiliation: Department of Cardiovascular Surgery, Huazhong University of Science and Technology, Wuhan, 430022, China.
authors.forename: Zhigang
authors.initials: Z
authors.lastname: Shui
authors.affiliation: Department of Cardiovascular Surgery, Huazhong University of Science and Technology, Wuhan, 430022, China.
authors.forename: Jinping
authors.initials: J
authors.lastname: Liu
authors.affiliation: Department of Cardiovascular Surgery, Huazhong University of Science and Technology, Wuhan, 430022, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Sun
authors.affiliation: Ion Channelopathy Research Center, Institute of Cardiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China.
authors.forename: Yimei
authors.initials: Y
authors.lastname: Du
authors.affiliation: Department of Biological Engineering, South-Central University for Nationalities, Wuhan, 430074, China.
authors.forename: Guoliang
authors.initials: G
authors.lastname: Hao
mesh_terms: D000109:Acetylcholine / Q000494:pharmacology*; D000200:Action Potentials / Q000187:drug effects* / Q000502:physiology; D001281:Atrial Fibrillation / Q000503:physiopathology*; D016275:Atrial Function / Q000187:drug effects / Q000502:physiology*; D006325:Heart Atria / Q000294:innervation; D006801:Humans; D066298:In Vitro Techniques
chemical_list: D000109:Acetylcholine