Activation of small conductance Ca²⁺ -activated K⁺ channels suppresses Ca²⁺ transient and action potential alternans in ventricular myocytes.

ABSTRACT: At the cellular level, cardiac alternans is observed as beat-to-beat alternations in contraction strength, action potential (AP) morphology and Ca²⁺ transient (CaT) amplitude, and is a risk factor for cardiac arrhythmia. The (patho)physiological roles of small conductance Ca²⁺ -activated K⁺ (SK) channels in ventricles are poorly understood. We tested the hypothesis that in single rabbit ventricular myocytes pharmacological modulation of SK channels plays a causative role for the development of pacing-induced CaT and AP duration (APD) alternans. SK channel blockers (apamin, UCL1684) had only a minor effect on AP repolarization. However, SK channel activation by NS309 resulted in significant APD shortening, demonstrating that functional SK channels are well e

SUBMITTER: Kanaporis G 

PROVIDER: S-EPMC9878619 | biostudies-literature | 2023 Jan

REPOSITORIES: biostudies-literature