Kalciokanavan

Kalciokanavan is the Finnish term for calcium channel, a class of ion channels embedded in cell membranes that selectively permit calcium ions (Ca2+) to enter the cytoplasm. Calcium entry serves as a key trigger for diverse cellular signaling pathways and is essential for translating electrical or chemical stimuli into intracellular responses.

Most studied are voltage-gated calcium channels (VGCCs) formed by a pore-forming alpha1 subunit and auxiliary beta, alpha2delta and gamma subunits. VGCCs are grouped into Cav1 (L-type), Cav2 (P/Q-, N-, and R-type) and Cav3 (T-type). They open upon membrane depolarization and differ in activation thresholds and inactivation. Other calcium-permeable channels, including store-operated and receptor-operated channels, also contribute Ca2+ influx in many cells.

Functions: Calcium entry through kalciokanavat regulates muscle contraction (cardiac and smooth), neurotransmitter and hormone secretion, enzyme activity, gene transcription, and synaptic plasticity. Calcium acts as a universal second messenger, shaping signaling patterns via local concentrations and frequency.

Regulation and pharmacology: Channel activity is modulated by voltage, subunits, intracellular messengers and drugs. Calcium channel blockers (dihydropyridines such as amlodipine and nifedipine; non-DHPs such as verapamil and diltiazem) reduce Ca2+ influx and are used for hypertension and some arrhythmias.

Clinical relevance: Abnormal kalciokanavan function is linked to cardiovascular and neurological disorders and pain. Research aims to target channel subtypes selectively to treat disease with fewer side effects.