Key Results
Concentration-dependent increases in intracellular Ca2+ and DMR response were observed upon the addition of MRGPRD agonists which were similar in rank order but with an approximately log-unit reduction in pEC50 between Ca2+ responses and DMR, respectively. Inhibition of Gq-G protein coupling abolished Ca2+responses whereas DMR responses were sensitive to Gi-G protein inhibition. The putative MRGPRD antagonists thyoradizine hydrochloride, and MU-6840, produced different patterns of inhibition between the two assays whereas PD123,319 was ineffective.