Evidence for P2Y1 P2Y2 P2Y6 and atypical UTP-sensitive receptors coupled to rises in intracellular calcium in mouse cultured superior cervical ganglion neurons and glia

摘要

class="enumerated" style="list-style-type:decimal">P2Y receptors are expressed in the nervous system and are involved in calcium signalling in neurons and glia. In the superior cervical ganglion (SCG), RT–PCR analysis indicated the presence of P2Y1,2&6 receptors. Rises in intracellular calcium in response to P2Y receptor stimulation were determined from adult mouse cultured SCG neurons and glia.ADP evoked suramin (100 μM)- and pyridoxalphosphate-6-azophenyl-2′,4′-disulphonic acid (PPADS, 30 μM)-sensitive rises in intracellular calcium in ∼80% of SCG neurons (EC50∼20 μM). ADP-evoked responses were abolished in neurons from P2Y1 receptor-deficient mice (responses to UTP were unaffected).The pyrimidines UTP (EC50∼85 μM) and UDP (EC50>90 μM) evoked PPADS- and suramin-sensitive responses in ∼70 and ∼20% of SCG neurons, respectively.In SCG glial cells, ADP (EC50∼30 μM) evoked calcium responses in ∼50% of glia. These were suramin and PPADS sensitive and essentially abolished in SCG glial cells cultured from adult P2Y1 receptor-deficient mice.UTP (EC50∼25 μM) and UDP (EC50>200 μM) evoked suramin- and pyridoxalphosphate-6-azophenyl-2′,5′-disulphonate-sensitive rises in calcium in ∼60 and 20% SCG glial cells, respectively.These results indicate the presence of several P2Y receptors coupled to an increase in intracellular calcium in the SCG: ADP-sensitive P2Y1 receptors and UDP-sensitive P2Y6 receptors in SCG neurons and glial cells, a novel UTP-sensitive P2Y receptor in SCG neurons and UTP- and ATP-sensitive P2Y2 receptors in SCG glia.