Potential functional roles of extracellular ATP in kidney and urinary tract.

P2 receptors are sensitive to adenosine triphosphate (ATP) and uridine triphosphate and can be divided into two major subtypes: P2X and P2Y receptors. They are specific membrane-bound receptors which when activated by extracellular ATP initiate a variety of biological effects. The P2X receptors are ligand-gated channels, whereas the P2Y receptors are coupled to G proteins linked to second-messenger systems. In this review, the potential functional roles of extracellular ATP in the kidney and lower urinary tract are discussed and briefly explored in the context of some specific renal and urinary tract abnormalities.