Stretch-Induced Increase in Ca²⁺-Spark Rate in Rabbit Atrial Cardiomyocytes Requires TRPA1 and Intact Microtubule Network.

ABSTRACT:

Background

Mechanical stretch of the myocardium is proarrhythmic and alters cellular Ca²⁺ handling, potentially involving cation nonselective mechano-sensitive ion channels. This study aimed to assess the presence and mechanisms of stretch-induced increase in Ca²⁺-spark rate (SiS) in isolated atrial cardiomyocytes.

Methods

Freshly isolated rabbit, pig, and human left atrial cardiomyocytes were stretched axially using glass microrods. Free cytosolic Ca²⁺ concentration was monitored using confocal microscopy at resting sarcomere length (≈1.79 μm) and during severe (≈12%) increase in sarcomere length.

Results

Diastolic stretch provoked SiS, which was prevented by disrupting microtubules with colchicine, but unaffected by inhibition of NAD

SUBMITTER: Fu J 

PROVIDER: S-EPMC12553421 | biostudies-literature | 2025 Sep

REPOSITORIES: biostudies-literature