Pharmacological characterization of a Chinese hamster ovary cell line transfected with the human CCK-B receptor gene.

A stable Chinese hamster ovary cell line expressing the human CCK-B receptor gene is described (hCCK-B.CHO). In radioligand binding experiments employing membranes derived from these cells the rank order of affinity estimated for a series of CCK receptor ligands (CCK-8S > CI988 > PD 135158 > pentagastrin > CCK-8NS > L-365,260 > CCK-4 > LY 288513 > devazepide > A71378 > lorglumide) was found to be in excellent agreement with CCK-B receptor pharmacology described in guinea-pig cortex. Functional coupling in hCCK-B.CHO cells was demonstrated using agonist stimulated mobilization of intracellular Ca2+, measured with the FURA-2 technique. The CCK-B receptor selective agonist CCK-4 stimulated the mobilization of intracellular Ca2+ with an estimated pEC50 value of 7.4. Consistent with CCK-B receptor pharmacology, the rank order of potency for antagonism of this response was observed to be PD 135158 > CI988 > L-365,260 >> devazepide > lorglumide. This cell line provides a powerful new tool for the evaluation and development of novel ligands acting at the human CCK-B receptor subtype.