Agonist-stimulated internalisation of the ligand-gated ion channel P2X(1) in rat vas deferens.

Using cell surface biotinylation and Western blotting, we investigated the extent to which native P2X(1) receptors in rat vas deferens are internalised after exposure to agonist. Exposure to 100 microM alpha,beta-meATP 30 min prior and during a 10 min biotinylation period resulted in a approximately 50% reduction in the amount of biotinylated P2X(1) receptor indicating that activation of the receptor by agonist induces receptor internalisation. Furthermore, biotinylation under saturating conditions suggests that once internalised, a rapid recycling of P2X(1) receptor back to the cell surface occurs. The physiological implications of these mechanisms in terms of receptor function are discussed.