Table 1: EC50 Values of four Gq-Coupled GPCRs Determined in the IP-One and Intracellular Calcium Assays

GPCR Agonist EC50(nM) (calcium assay) (a) EC50(nM) (IP-One assay) (b) Ratio b/a
M1R Carbachol 16.1 535 33.2
V1bR Vasopressin 0.032 1.10 34.4
FFAR1 GW9508 5700 6300 1.1
NPSR NPS 0.22 0.41 1.9