Measuring Local Gradients of Intramitochondrial [Ca ²⁺ ] in Cardiac Myocytes During Sarcoplasmic Reticulum Ca ²⁺ Release

Abstract

We developed methods to measure spatiotemporal [Ca(2+)](mito) gradients quantitatively during excitation-contraction coupling. The amplitude and kinetics of [Ca(2+)](mito) transients differ significantly from those in the cytosol and are respectively higher and faster near the Z-line versus M-line. This approach will help clarify SR-mitochondrial Ca(2+) signaling.