FIGURE 4.

Biological activity at chimeric CCK receptor constructs. Shown are curves representing the abilities of GI181771X to stimulate intracellular calcium responses in wild-type and chimeric CCK receptor-bearing cells (in which there were significant responses over basal values), with data plotted relative to the maximal responses of each cell line to the natural agonist control, CCK. Also shown are bar graphs of the intracellular calcium responses in cells expressing all of the constructs in each series, with constructs based on the type 1 CCK receptor separated from those based on the type 2 CCK receptor. Data represent mean ± S.E. of values from four to six independent experiments performed in duplicate.