“…Kitayama et al reported that in the presence of plasma membrane Gα s , prostaglandin I2 (IP), 5-hydroxytryptamine 5-HT4 (5-HT4), dopamine D1 (D1), adenosine A2A (A2A), and vasoactive intestinal polypeptide (VIP) receptors, immunoreactivity was observed in human odontoblasts [15]. Furthermore, in the presence of extracellular Ca 2+ , the application of IP, 5-HT4, D1, A2A, and VIP receptor agonists increased intracellular cAMP levels.…”