STABLE EXPRESSION OF HUMAN KININ B-1 RECEPTOR IN 293 CELLS - PHARMACOLOGICAL AND FUNCTIONAL-CHARACTERIZATION

1 We compared the binding properties of [H-3]-desArg(10)-[Leu(9)]-kall idin, a radiolabelled kinin B-1 receptor antagonist, to membranes from IMR-90 human embryonic fibroblasts and from 293 cells transiently or stably transfected with the human B-1 receptor. 2 The dissociation con stant (K-D) of [H-3]-desArg(10)-[Leu(9)]-kallidin and the affinity of several kinin receptor agonists and antagonists were similar between t he native and cloned receptor, either transiently or stably expressed in 293 cells. In IMR-90 cells, the rank order of potency was that expe cted for a kinin B-1 receptor. 3 The receptors transiently or stably e xpressed in 293 cells were fully functional with respect to their sign alling properties. Phosphoinositide hydrolysis was increased in a conc entration-dependent manner by the B-1 receptor agonist, desArg(10)-kal lidin. Functional coupling to the calcium pathway was also demonstrate d for the native and stably expressed human B-1 receptor. 4 In conclus ion, the established stable and functional 293 cell clone may provide an important tool for further analysis of the molecular mechanisms inv olved in binding, activation, and coupling of the kinin B-1 receptor.