Muscarinic type-1 receptors contribute to IK,ACh in human atrial cardiomyocytes and are upregulated in patients with chronic atrial fibrillation.

ABSTRACT: BACKGROUND:Basal and acetylcholine-gated inward-rectifier K+-currents (IK1 and IK,ACh, respectively) are altered in atrial fibrillation (AF). Gi-protein-coupled muscarinic (M) receptors type-2 are considered the predominant receptors activating IK,ACh. Although a role for Gq-coupled non-M2-receptor subtypes has been suggested, the precise regulation of IK,ACh by multiple M-receptor subtypes in the human atrium is unknown. Here, we investigated M1-receptor-mediated IK,ACh regulation and its remodeling in chronic AF (cAF). METHODS AND RESULTS:M1-receptor mRNA and protein abundance were increased in atrial cardiomyocyte fractions and atrial homogenates from cAF patients, whereas M2-receptor levels were unchanged. The regulation of IK,ACh by M1-receptors was investigated in right-atrial cardio

SUBMITTER: Heijman J 

PROVIDER: S-EPMC5815374 | biostudies-literature | 2018 Mar

REPOSITORIES: biostudies-literature