Investigation of fundo-antral reflex in human beings

Aim: To examine the sensory and motor response(s) of the stomach following fundic distention and to assess whether cholinergic mechanisms influence these responses. Methods: Fundic tone, gastric sensory responses and antral motility were evaluated in eight healthy volunteers after a probe with two sensors was placed in the antrum and a highly compliant balloon in the fundus. Isobaric balloon distentions were performed with a barostat. Study was repeated in six volunteers after intravenous atropine was given. Results: Fundic distention induced large amplitude antral contractions in all subjects. The area under the curve was higher (P<0.05) during fundic distention. First sensation was reported at 12±4 mmHg, moderate sensation at 18±4 mmHg and discomfort at 21±4 mmHg. Discomfort was associated with a decrease in antral motility. After atropine was given, the area under the curve of pressure waves and fundic tone decreased (P<0.05). Sensory thresholds were not affected. Conclusions: Fundic balloon distention induces an antral motor response, the fundo-antral reflex, which in part may be mediated by cholinergic mechanisms.