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Chapter 6 (page 25)
Electrical Potential Difference at the Gastroduodenal Mucosal Junction
It has long been known that the mucosal surface of the upper gastrointestinal tract is
electrically negative with respect to serosa, skin and blood. The size of the electrical
potential difference (PD), measured in millivolts (mv), is greatest in the oxyntic mucosal
zone in the corpus of the stomach. Andersson and Grossman (1965) found that the
mucosal surface of the corpus was at a potential of -44mV with respect to blood, while the
figures for the "antrum" and duodenal bulb were -35mV and -7mV respectively. When an
intraluminal electrode was manipulated from the duodenum into the stomach, there was a
change to a more negative potential in the stomach. The greatest change in PD occurred
as the electrode passed from the duodenum into the stomach. It occurred abruptly, was
uniform, sharp, well-defined and coincided with what they called the anatomical
sphincter (the pyloric ring) and the mucosal border. It was shown by these authors as
well as by Durbin (1967) that the change in PD was a reliable means of identifying the
During endoscopic studies of the pylorus, Blackwood (1969) correlated visual
identification of the pyloric ring with PD measurements. In all 7 normal subjects a
significant PD change occurred within 1.0 cm of the true pyloric ring. In 2 studies in
which a PD change occurred 3.0 to 4.0 cm beyond a visualized ring, the latter was shown
to be a false ring, mimicking the pylorus and caused by antral deformity.
Geall et al (1970) confirmed that PD measurements between the mucosal surface and
venous blood gave identical values to the PD between mucosa and serosa, but that
mucosa-skin PD measurements varied and were less reliable. They thought that the
technique might have various applications, e.g. in the investigation of transport
During experimental studies PD measurements were used as an accurate method of
identifying the gastroduodenal mucosal junction in canines by Isenberg and Csendes
(1972). Fisher and Cohen (1973) confirmed that the junction of the stomach and
duodenum as seen radiologically in normal human subjects (Chap. 11, 13), was marked
by a PD change of -33mV.
Kaye et al (1976) and White et al (1981) used PD measurements to determine the
gastroduodenal mucosal junction in humans.
A significant change in electrical potential difference (PD) occurs at the gastroduodenal
mucosal junction, located on, or close to, the top of the pyloric ring (the right pyloric
loop) (Chaps. 3, 5). PD measurements are a reliable means of determining the
gastroduodenal mucosal junctions in the intact, living canine and human stomachs.
- Andersson S, Grossman MI. Profile of pH, pressure and potential difference at
gastroduodenal junction in man. Gastroenterology l965, 49, 364-371.
- Blackwood WD. Pylorus identification. Gastroenterology l969, 57, 163-167.
- Durbin RP. Electrical potential difference of the gastric mucosa. In: Handbook
of Physiology Sect 6: Alimentary Canal, Vol 2 : Secretion, edit Code CF, Heidel
W. Amer Physiol Soc, Washington DC l968, pp 879-888.
- Fisher R, Cohen S. Physiological characteristics of the human pyloric sphincter.
Gastroenterology l973, 64, 67-75.
- Geall MG, Code CF, McIlraith DC, et al. Measurement of gastrointestinal
transmural electric potential difference in man. Gut l970, 11, 34-37.
- Isenberg JI, Csendes A. Effect of octapeptide of cholecystokinin on canine
pyloric pressure. Amer J Physiol l972, 222, 428-431.
- Kaye MD, Mehta SJ, Showalter JP. Manometric studies of the human pylorus.
Gastroenterology l976, 70, 477-480.
- White CM, Poxon V, Alexander-Williams J. A study of motility of normal
human gastroduodenal region. Dig Dis Sci l98l, 26, 609-617.
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