Calcium ion release from intracellular stores

"Calcium ion release from intracellular stores" is not a single molecular target but rather a fundamental cellular process involving the mobilization of stored Ca^2+ ions—primarily from the endoplasmic reticulum (ER) and sarcoplasmic reticulum (SR)—into the cytoplasm. This event is central to numerous physiological functions including signal transduction, muscle contraction, neurotransmitter and hormone secretion, and regulation of cell fate decisions such as proliferation and apoptosis[1][2][3][4]. The main molecular mediators are inositol 1,4,5-trisphosphate receptors (IP3Rs) and ryanodine receptors (RyRs), which act as gated channels on ER/SR membranes. These channels open in response to second messengers like IP3 or changes in cytosolic Ca^2+, allowing rapid elevation of cytoplasmic calcium levels. This process is tightly regulated; dysregulation can contribute to diseases such as cardiac arrhythmias, neurodegeneration via excitotoxicity, asthma through altered airway smooth muscle contractility[6], among others. While many drugs modulate this pathway by targeting its key protein components—for example dantrolene inhibits RyR-mediated SR Ca^2+ release—the term "calcium ion release from intracellular stores" does not refer to a discrete druggable entity but rather an essential biological mechanism. "Intracellular calcium is stored in organelles which repetitively release and then reaccumulate Ca^2+ ions in response to specific cellular events: storage sites include mitochondria and the endoplasmic reticulum."[4] "Release from [the ER] is mediated by the inositol 1,4,5-trisphosphate receptor (IP3R) and ryanodine receptor families..."[3] Because it describes a process rather than an individual protein/receptor/enzyme/transporter/etc., it should not be considered a canonical therapeutic target. For structured data purposes you should instead specify one of its principal molecular effectors—such as "Inositol 1,4,5-trisphosphate receptor type 1" or "Ryanodine receptor type 1".

Other names

Intracellular calcium releaseRelease of Ca2+ from intracellular storesER calcium releaseSR calcium release