Ischemia Enhances the Acute Stretch-Induced Increase in Calcium Spark Rate in Ventricular Myocytes.

ABSTRACT: Introduction: In ventricular myocytes, spontaneous release of calcium (Ca2+) from the sarcoplasmic reticulum via ryanodine receptors ("Ca2+ sparks") is acutely increased by stretch, due to a stretch-induced increase of reactive oxygen species (ROS). In acute regional ischemia there is stretch of ischemic tissue, along with an increase in Ca2+ spark rate and ROS production, each of which has been implicated in arrhythmogenesis. Yet, whether there is an impact of ischemia on the stretch-induced increase in Ca2+ sparks and ROS has not been investigated. We hypothesized that ischemia would enhance the increase of Ca2+ sparks and ROS that occurs with stretch. Methods: Isolated ventricular myocytes from mice (male, C57BL/6J) were loaded with fluorescent dye to detect Ca2+ sparks (4.6 μM Fluo-4,

SUBMITTER: Cameron BA 

PROVIDER: S-EPMC7179564 | biostudies-literature | 2020

REPOSITORIES: biostudies-literature