Simultaneous activation of the small conductance calcium-activated potassium current by acetylcholine and inhibition of sodium current by ajmaline cause J-wave syndrome in Langendorff-perfused rabbit ventricles.

ABSTRACT:

Background

Concomitant apamin-sensitive small conductance calcium-activated potassium current (I_KAS) activation and sodium current inhibition induce J-wave syndrome (JWS) in rabbit hearts. Sudden death in JWS occurs predominantly in men at night when parasympathetic tone is strong.

Objective

The purpose of this study was to test the hypotheses that acetylcholine (ACh), the parasympathetic transmitter, activates I_KAS and causes JWS in the presence of ajmaline.

Methods

We performed optical mapping in Langendorff-perfused rabbit hearts and whole-cell voltage clamp to determine I_KAS in isolated ventricular cardiomyocytes.

Results

ACh (1 μM) + ajmaline (2 μM) induced J-point elevations in all (6 male and 6 female) hearts from 0.01± 0

SUBMITTER: Fei YD 

PROVIDER: S-EPMC7796982 | biostudies-literature | 2021 Jan

REPOSITORIES: biostudies-literature