Adenosine 5'-triphosphate (ATP) can act as an extracellular signal that regulates various cellular functions. The present study aimed to determine which purinoceptors play a role in ATP ] i increase, and UTP and α,β-MeATP had no effect. The potency order of ATP analogs (2-MeSATP > ATP >> UTP) suggested that P2Y 1 and P2Y 12 play a significant role in the cellular response to ATP. RT-PCR revealed that P2X 2,4,7 and P2Y 1,2,10,12,14 were expressed in acinar cells. Ca 2+ -dependent exocytotic secretion of amylase was detected in parotid glands. These findings indicated that ATP activates P2Y receptors more than

Pituitary adenylyl cyclase-activating polypeptide (PACAP) is a bioactive peptide with diverse effects in the nervous system. The present study investigated whether stimulation of PACAP ] i in satellite cells; however, this was partly inhibited in neurons. U73122 or xestospongin C treatment completely and partly abrogated [Ca 2+ ] i changes in satellite cells and in neurons, respectively, whereas VPAC1R and VPAC2R agonists increased [Ca 2+ ] i in satellite cells only. This is the first report demonstrating the expression of PACAPRs specifically, VPAC1 and VPAC2 in SCG and providing evidence for PACAP38-induced [Ca 2+