M2046 Bile Acids Cause Relaxation of Lower Esophageal Sphincter Through G Protein-Coupled Bile Acid Receptors

Objectives: Bile acids inhibit contraction of the gallbladder and intestine through the G-protein-coupled bile acid receptor (GPBAR). Perfusion of the esophagus with bile and acid (HCl) decreases lower esophageal sphincter (LES) pressure. The effects of bile acids on LES motility are not clear. The purpose of the present study was to investigate the effects of bile acids on LES motility in vitro. Materials and Methods: We measured the relaxation of muscle strips isolated from guinea pig and rat LES caused by bile acids or the selective GPBAR agonist RG-239. Reverse transcription polymerase chain reaction (RT-PCR) was performed to determine GPBAR expression in rat LES. Results: In carbachol-contracted guinea pig LES strips, lithocholic acid (LCA), deoxycholic acid (DCA), chenodeoxycholic acid (CDCA), and cholic acid (CA) produced relaxation in a concentration-dependent