Salivary calcium ions

Salivary calcium ions refer to the cytosolic calcium ions ([Ca²⁺]ᵢ) in salivary gland acinar cells, which serve as a critical second messenger regulating fluid secretion and ion transport. Stimulation by neurotransmitters triggers inositol 1,4,5-trisphosphate (IP₃)-mediated release of Ca²⁺ from endoplasmic reticulum stores via IP₃ receptors (primarily IP₃R2 and IP₃R3), initiating a localized apical-to-basolateral Ca²⁺ wave that activates Ca²⁺-dependent K⁺, Cl⁻ channels, and transporters like Na⁺-K⁺-2Cl⁻ cotransporter to drive transepithelial Cl⁻ flux and osmotic water movement through aquaporin-5. Sustained [Ca²⁺]ᵢ elevation requires store-operated Ca²⁺ entry (SOCE) via plasma membrane channels including Orai1, TRPC1, TRPC3, gated by ER sensors STIM1 and STIM2, ensuring prolonged secretion. Dysregulated Ca²⁺ signaling, such as excessive SOCE or ROS-activated TRPM2 channels, contributes to salivary gland dysfunction, cell damage, ER stress, and conditions like xerostomia, but calcium ions themselves are not pursued as direct therapeutic targets; instead, modulators like IP₃R or SOCE components are studied.

Other names

cytosolic calcium ionsintracellular calcium ions ([Ca²⁺]ᵢ)salivary gland calcium signals