Magnesium Ions Moderate Calcium-Induced Calcium Release in Cardiac Calcium Release Sites by Binding to Ryanodine Receptor Activation and Inhibition Sites.

ABSTRACT: Ryanodine receptor channels at calcium release sites of cardiac myocytes operate on the principle of calcium-induced calcium release. In vitro experiments revealed competition of Ca²⁺ and Mg²⁺ in the activation of ryanodine receptors (RyRs) as well as inhibition of RyRs by Mg²⁺. The impact of RyR modulation by Mg²⁺ on calcium release is not well understood due to the technical limitations of in situ experiments. We turned instead to an in silico model of a calcium release site (CRS), based on a homotetrameric model of RyR gating with kinetic parameters determined from in vitro measurements. We inspected changes in the activity of the CRS model in response to a random opening of one of 20 realistically distributed RyRs,

SUBMITTER: Iaparov B 

PROVIDER: S-EPMC8821920 | biostudies-literature | 2021

REPOSITORIES: biostudies-literature