Bitter compounds mixture (10 mM PTC, 10 mM denatoneum benzoate, 1.5 mM quinine, and 5 mM D-[-]salicin) was introduced to FVB mice through oral gavage. CCK receptor antagonist YM022 (250 μM) was administered 30 min before oral gavage of bitter compounds mixture. After 1 h gavage plasma CCK concentration was measured by EIA assay (A). Intestine was collected 16 h later, and both mRNA and protein levels for ABCB1 was analyzed by RT-qPCR (B) and immunoblotting (C), respectively. Immunoblotting data are shown for 3 individual mice of each group. Data are mean ± SEM, n=4 for three separate experiments. 1, control; 2, bitter compounds mixture; 3, YM022; 4, YM022 + bitter compounds mixture; TR, transferrin receptor.