Potential difference across the pyloric antrum.

Abstract

Previous work has shown the presence of a potential difference (PD) across the fundic portion of the stomach and a smaller PD across the pyloric antrum. All of the reported measurements on the pylorus have been performed with in vitro techniques. The magnitude of the PD across the pyloric antrum was determined when its blood supply was intact. Isoelectric electrodes were placed opposite each other across the wall with isotonic saline agar making contact with the surfaces. The PD's were measured with a recording potentiometer. The average PD (mucosa negative) across the fundus, pyloric antrum and duodenum was 64 mv, 48 mv and 11 mv, respectively. There was a steep gradient of PD at the duodenal-pyloric junction. The PD of the pylorus arises from its own inherent electromotive forces. The PD like that of the fundus declines rapidly following interruption of the blood supply. The injection of Mecholyl results in a reversible decrease in the fundic potential and relatively little change in the pyloric PD.