Fig. 1.

Structure of compound 1 and effects on the cloned human GLP-1 receptor and the closely related GIP, GLP-2, and glucagon receptors, all expressed in BHK cells. (a) cAMP functional assay by using either the cloned human GLP-1, GLP-2, glucagon, or GIP receptors. The EC₅₀ value for GLP-1 and compound 1 was 23 pM and 1.4 μM, respectively. (b) Binding assay for the cloned human GLP-1 receptor. Both assays were carried out by using plasma membranes prepared from BHK cells expressing the different cloned human receptors. Data are from one of three to five identical experiments, in each experiment all concentrations were tested in triplicate.