CHEMBL5736064

Human NK-1 assay: The affinity of compounds of the invention for the NK-1 receptor was evaluated in CHO recombinant cells which express the human NK-1 receptor. Membrane suspensions were prepared from these cells. The following radioligand: [3H] substance P (PerkinElmer Cat #NET111520) was used in this assay. Binding assays were performed in a 50 mM Tris/5 mM MnCl2/150 mM NaCl/0.1% BSA at pH 7.4. Binding assays consisted of 25 μl of membrane suspension (approximately 5 μg of protein/well in a 96 well plate), 50 μl of compound or reference ligand (Substance P) at increasing concentrations (diluted in assay buffer) and 2 nM [3H] substance P. The plate was incubated 60 min at 25° C. in a water bath and then filtered over GF/C filters (Perkin Elmer, 6005174, presoaked in 0.5% PEI for 2 h at room temperature) with a Filtration unit (Perkin Elmer). The radioactivity retained on the filters was measured by using the TopCount-NXT reader (Packard). Competition curves were obtained for compounds of the invention and the concentrations of compounds which displaced 50% of bound radioligand (IC50) were determined and then apparent inhibition constant Ki values were calculated by the following equation: Ki=IC50/(1+[L]/KD) where [L] is the concentration of free radioligand and KD is its dissociation constant at the receptor, derived from saturation binding experiments (Cheng and Prusoff, 1973).