An investigation of lower oesophageal redox potentials in gastro-oesophageal reflux patients and healthy volunteers

Oesophageal electrical properties are thought to be important in the development of gastro-oesophageal reflux. This study simultaneously monitored the intraoesophageal pH and redox potentials in 18 patients with gastro-oesophageal reflux symptoms and 15 asymptomatic controls, for a 24 h period. The pH and redox electrodes were positioned 5 cm proximal to the lower oesophageal sphincter, the position of which had been determined by manometry. Since significantly different behaviour was observed during the day and night, the data were divided into periods of waking and sleeping. Data were analysed for acid reflux (pH < 4) and transients in the redox potential-time curve. Both patients and normal subjects showed negative redox transients which were more frequent and pronounced at night than during the day, and which were uncorrelated with acid reflux. The only parameter which was significantly different between normal and refluxing groups was the amount of nocturnal redox activity, which was lower in refluxing subjects than in normals. Some possible hypotheses for these observations, and the origin of the redox species, are discussed.