The influence of the novel 5‐HT1A agonist R137696 on the proximal stomach function in healthy volunteers

As fundic dysaccommodation represents one of the pathophysiological mechanisms underlying functional dyspepsia, gastric relaxant agents may serve as a new treatment of this disorder. Previous studies have suggested the involvement of 5HT1 receptors in the control of gastric tone. Our aim was to study the effect of R137696, a novel 5HT1A agonist, on fundus sensorimotor function in healthy volunteers. The effect of single oral doses (1–2 mg) R137696 was evaluated in a double‐blind, placebo‐controlled manner on fasting fundic volume, visceral perception, distension‐evoked symptoms and fundic compliance in 21 healthy male subjects. R137696 increased the proximal stomach volumes in a dose‐dependent manner. Distention‐evoked symptoms or distention and discomfort threshold were not altered by R137696. A logistic regression model, characterizing the relationships between the volume and the visual analogue scale score for dyspeptic symptoms (nausea, fullness, discomfort, pain and satiety) as a sigmoidal curve, revealed that R137696 had no effect on distension‐induced discomfort, fullness, pain and satiety compared to placebo. R137696 relaxes the gastric fundus in fasting conditions but has no effect on distension‐evoked dyspeptic symptoms in healthy volunteers.