Related Experiment Video
Updated: Jan 27, 2026

Simultaneous Laryngopharyngeal and Conventional Esophageal pH Monitoring
Published on: December 14, 2020
Effect of EP1 Receptor Antagonist on Transient Lower Esophageal Sphincter Relaxations in Humans
Akinari Sawada1, Atsushi Hashimoto2, Risa Uemura2
1Department of Gastroenterology, Osaka City University Graduate School of Medicine, Osaka, Japan, m1164972@med.osaka-cu.ac.jp.
Background/Aims:
Transient lower esophageal sphincter relaxations (TLESRs) are the major cause of gastroesophageal reflux. Recently, an EP1 receptor antagonist, ONO-8539, showed the reduction of TLESRs in monkeys. However, its effect on TLESRs in humans remains unclear. This study investigated the effect of ONO-8539 on postprandial TLESRs in healthy male subjects.
Methods:
Twenty-seven subjects participated in this placebo-controlled, cross-over study. The subjects received either placebo or ONO-8539 (450 mg) after a standardized breakfast. A 30-min basal recording was performed 4 h after drug administration. Subsequently, TLESR recordings were performed after a high-fat test meal for 3 h. The examination was repeated at least 7 days from the first evaluation for washout.
Results:
Thirteen patients were ultimately analyzed. The basal lower esophageal sphincter pressure was not different between the 2 groups (16.3 and 18.0 mm Hg for placebo and ONO-8539, respectively; p = 0.88). ONO-8539 significantly reduced the number of TLESRs from 15.0 to 12.0 for 3 h (p < 0.05). The proportion of terminating events of TLESRs was significantly different between the 2 groups (p < 0.05). No events and swallowing terminated more TLESRs with ONO-8539 than with placebo.
Conclusions:
ONO-8539 suppressed TLESRs mildly. EP1 receptor may be involved with the mechanism of human TLESRs.
More Related Videos
12:16Production, Characterization and Potential Uses of a 3D Tissue-engineered Human Esophageal Mucosal Model
Published on: May 18, 2015
10:51Reverse Yeast Two-hybrid System to Identify Mammalian Nuclear Receptor Residues that Interact with Ligands and/or Antagonists
Published on: November 15, 2013
Related Concept Videos
Drug-Receptor Interaction: Antagonist
Antagonists can be classified as competitive or noncompetitive based on their...
Antiasthma Drugs: Muscarinic Receptor Antagonists
Antimuscarinic agents compete with ACh for the same binding site on the muscarinic receptors. By binding to these receptors, they inhibit the downstream effects of ACh and block the parasympathetic...
Adrenergic Antagonists: ɑ and β-Receptor Blockers
Drugs Affecting GI Tract Motility: Dopamine Receptor Antagonists
Adrenergic Antagonists: Pharmacological Actions of ɑ-Receptor Blockers
α1-blockers: These drugs inhibit α1-adrenoceptors on smooth muscle cells, resulting in vasodilation. This vasodilation lowers blood pressure, making α1-blockers valuable in treating hypertension. Additionally,...
Adrenergic Antagonists: Pharmacological Actions of β-Receptor Blockers