Transmission of electrical activity through the gastroduodenal junction

Abstract

The electrical and mechanical activities of the gastroduodenal junction were studied in isolated cat preparations, using the pressure-electrode technique. The spontaneous electrical activity of the pyloric antrum consists of periodic depolarizations, the configuration of which is somewhat more complex than that of comparable potentials recorded from the longitudinal muscle layer of the small intestine. Like their intestinal counterparts these antral slow waves may be associated with spike potentials which are thought to initiate contractions. The electrical activity at the gastroduodenal junction consists of a combination of antral and duodenal slow waves, sometimes accompanied by spike potentials. In the proximal duodenum, antral slow waves are represented by periodic depolarizations which may be associated with spike potentials followed by contractions. Because of the extension of the antral slow waves into the proximal duodenum, contractions initiated in the antrum may also extend into the proximal duodenum. It is concluded that the gastroduodenal junction is a transition zone, coordinating the electrical and corresponding mechanical activities of the antrum and proximal duodenum.