Intracellular calcium release

Intracellular calcium release is a fundamental physiological process rather than a discrete molecular target or receptor. It describes the rapid mobilization of calcium ions (Ca2+) from internal storage organelles, such as the endoplasmic reticulum (ER) and sarcoplasmic reticulum (SR), into the cytoplasm [1]. This process is primarily executed by two major families of high-conductance ion channels: the Ryanodine receptors (RyRs), which are often triggered by calcium-induced calcium release (CICR), and the Inositol 1,4,5-trisphosphate receptors (IP3Rs), which are activated by secondary messengers generated via G protein-coupled receptor or tyrosine kinase signaling [2][3]. This release is a critical step in translating extracellular signals into specific cellular responses, including excitation-contraction coupling in muscles and neurotransmitter release in neurons. Clinically, the dysregulation of intracellular calcium release is a hallmark of several life-threatening conditions. In cardiac tissue, leaky RyR2 channels contribute to heart failure and arrhythmias, such as Catecholaminergic Polymorphic Ventricular Tachycardia (CPVT), while mutations in skeletal RyR1 lead to malignant hyperthermia [4]. Pharmacological intervention usually involves stabilizing these channels or inhibiting their opening; for instance, Dantrolene is a well-established RyR1 antagonist used to treat malignant hyperthermia, and Flecainide has been shown to suppress arrhythmogenic calcium waves by modulating RyR2 [5]. Because calcium is a ubiquitous second messenger involved in nearly all cellular functions, therapeutic strategies must achieve high tissue and isoform specificity to minimize systemic toxicity and profound safety concerns related to muscle and cardiac function.

Other names

Calcium mobilizationCalcium signalingStore-operated calcium releaseCa2+ releaseCalcium-induced calcium release (CICR)

Modulation (inhibition or activation) of specialized intracellular ion channels, primarily Ryanodine receptors (RyRs) and Inositol 1,4,5-trisphosphate receptors (IP3Rs), located on the endoplasmic or sarcoplasmic reticulum membranes to control the flux of calcium ions into the cytosol.