title: Serum positive for the autoantibody against the β(1)-adrenoceptor from Chinese patients with congestive heart failure decreases I(ss) in mouse cardiac myocytes.
abstract: Autoantibodies targeting the β(1)-adrenergic receptor (AAB-β(1)) display agonist-like effects, which may have a pathogenic role in the progression of heart failure. Here, we used the electrophysiological recordings to explore the effects of AAB-β(1)-positive serum from Chinese patients with heart failure on the activity of the peak transient outward potassium current (I(to)) and the end 50 ms steady-state potassium current (I(ss)) in mouse cardiac myocytes. We found that the AAB-β(1)-positive serum had no effect on the activity of I(to), but it produced a decrease in the currents of I(ss). A low concentration of positive serum (1/100) had a small inhibitory effect on I(ss). However, positive serum at 1 : 10, 1 : 20, and 1 : 50 significantly decreased I(ss). The concentration-dependence analysis showed that the EC(50) of AAB-β(1)-positive serum was 1/60.24 and its nH was 2.86. It indicated that the AAB-β(1) could inhibit I(ss) in mouse cardiomyocyte in a concentration-dependent manner.
authors.affiliation: Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education and Chinese Ministry of Public Health, Jinan 250012, China.
authors.forename: Yuan-yuan
authors.initials: YY
authors.lastname: Wang
authors.forename: Zhi-Yong
authors.initials: ZY
authors.lastname: Ma
authors.forename: Xiao-Dong
authors.initials: XD
authors.lastname: Li
authors.forename: Jian-chun
authors.initials: JC
authors.lastname: Wang
authors.forename: Wei
authors.initials: W
authors.lastname: Zhang
authors.forename: Li
authors.initials: L
authors.lastname: Li
authors.forename: Yun
authors.initials: Y
authors.lastname: Zhang
mesh_terms: D000200:Action Potentials; D000818:Animals; D001323:Autoantibodies / Q000097:blood* / Q000494:pharmacology*; D002681:China; D006333:Heart Failure / Q000276:immunology* / Q000378:metabolism; D006801:Humans; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D032383:Myocytes, Cardiac / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D018342:Receptors, Adrenergic, beta-1 / Q000276:immunology* / Q000378:metabolism
chemical_list: D001323:Autoantibodies; D018342:Receptors, Adrenergic, beta-1