Figure 1.

(A) Concentration-dependency of somatostatin-28, somatostatin-14, L-362,855, BIM-23027 and BIM-23056-mediated inhibition of forskolin (10 μM)-stimulated cyclic AMP formation in CHOsst₅ cells. (B) Depicts both the inhibitory and stimulatory response phases of the above agonists on an expanded ordinate scale from the same data set. For subsequent measurement of cyclic AMP, CHOsst₅ cells were suspended in DMEM supplemented with 0.5 mM IBMX, 0.02 mg ml⁻¹ bacitracin and 10 μM forskolin and the indicated concentration of agonist for 10 min. Cyclic AMP levels were measured as described in the Methods. Data are expressed as a percentage of the 10 μM forskolin response and are the means ±s.e.mean of 4–5 experiments performed in triplicate.