Measurement of electrical potentials of the human rectum and pelvic colon in normal and aldosterone-treated patients

摘要: A method is described which allows rapid measurement of the electrical potential difference across colonic mucosal epithelium to be carried out during routine sigmoidoscopy. The differences measured had a mean value 25 mV (range 4 51 mV) in 27 subjects with normal bowel. Six hours after two intravenous injections 0·5 mg aldosterone risen 60 37 101 mV). time course responses studied single injection showed that allowance rose within four and fallen again 18 hours. Urinary sodium concentrations sodium/potassium ratios fell injections, changes being similar colon. Sodium concentration stool fluid also fell. chloride was consistent passive distribution according electrochemical gradient, but potassium considerably greater than expected from distribution, suggesting actively secreted into lumen