Manometric studies of the human pylorus.

The human gastroduodenal junction was investigated by means of simultaneous measurements of pressure and potential difference between skin and mucosa. An accurate and circumferentially sensitive miniature transducer assembly failed to reveal a zone of elevated pressure at the gastroduodenal junction of 8 fasting, healthy, young subjects. Additional studies were carried out with a six-lumen perfused catheter system, in which three of the pressure-transmitting catheters had openings arranged circumferentially at the same axial level. Measurements of pressure and potential difference were obtained basally during intraduodenal infusion of hydrochloric acid and after intraduodenal instillation of olive oil. In only 1 of 10 subjects was a tonic elevation in pressure recorded simultaneously by all three leads at the gastroduodenal junction. The normal human pylorus, therefore, is not reliably demonstrable as a high pressure zone.