Intracellular calcium overload

Intracellular calcium overload is a pathological state characterized by the excessive accumulation of calcium ions (Ca2+) within the cytosol or organelles, exceeding the cell's buffering and extrusion capacity (StatPearls: Calcium Homeostasis, 2023). Under physiological conditions, calcium serves as a vital second messenger regulating muscle contraction, neurotransmitter release, and gene expression. However, during conditions such as ischemia, oxidative stress, or genetic mutations in ion channels, the homeostatic balance is disrupted, leading to sustained high concentrations of intracellular calcium (NCBI: PMC4016956). This overload triggers deleterious pathways, including the activation of calcium-dependent enzymes like calpains and phospholipases, mitochondrial dysfunction, and the induction of apoptotic or necrotic cell death (Nature Reviews Molecular Cell Biology, 2018). It is a central mechanism in the pathogenesis of myocardial infarction, heart failure, stroke, and various neurodegenerative diseases (Journal of Clinical Investigation, 2013). Therapeutic strategies do not target the 'overload' directly but rather the specific channels, transporters, and receptors—such as L-type calcium channels or ryanodine receptors—that facilitate the abnormal calcium flux (Frontiers in Pharmacology, 2020).

Other names

Cytosolic calcium overloadCalcium dyshomeostasisCalcium toxicityMitochondrial calcium overloadCa2+ overload

Reduction of cytosolic calcium levels through the blockade of influx channels (e.g., L-type calcium channels) or the inhibition of intracellular release channels (e.g., ryanodine receptors) to prevent pathological enzyme activation and cell death.