FIGURE 3.

Receptor binding characteristics of chimeric CCK receptor constructs. Shown are curves representing the abilities of GI181771X to compete for saturable binding of the CCK receptor subtype-selective benzodiazepine radioligands, ¹²⁵I-BDZ-1 and ¹²⁵I-BDZ-2, to membranes isolated from CHO cell lines expressing wild-type and chimeric CCK receptors. Saturable binding of the benzodiazepine radioligands was determined by competition with 1 μm concentration of the analogous non-radioactive benzodiazepine ligand (BDZ-1 or BDZ-2). Data represent mean ± S.E. of values from three to five independent experiments performed in duplicate.