Adenosine triphosphate mobilizes cytosolic calcium and modulates ionic currents in mouse taste receptor cells

Abstract

By using photometry and the patch clamp technique, we identified P 2Y-like receptors in mouse taste receptor cells (TRCs) and found them to be coupled to Ca 2+ mobilization and ionic current modulation. Particularly, adenosine triphosphate (ATP) and the P 2Y agonist 2-methylthio-ATP increased intracellular Ca 2+ by stimulating the phosphoinositide pathway, whereas β,γ-methylene- d-ATP, a P 2X agonist, was ineffective. In a distinctive TRC subpopulation, ATP closed Ca 2+ channels. This regulation may underlie the negative feedback tuning neurotransmitter release. By mobilizing intracellular Ca 2+, ATP activated Ca 2+-dependent Cl − channels, the intracellular event that may universally occur upon taste stimulation triggering IP 3 formation and Ca 2+ release in the TRC cytoplasm.