title: A comparison of methods for measurement of rectal potential difference in man: effects of rectal infusion of amiloride.
abstract: 1. Two methods for measurement of rectal potential difference in man were compared. A saline-filled catheter technique gave more reproducible results and was better tolerated by patients than the solid probe technique. 2. Infusion of amiloride at a concentration of 4 x 10(-6) mol/l in saline produced a variable fall of potential difference in six normal subjects. Dose-response curves in two subjects showed that complete inhibition of rectal difference occurred at 4 x 10(-5) mol/l and 4 x 10(-6) mol/l respectively. 3. This finding provides additional evidence that rectal potential difference in man results from electrogenic ion transport across the mucosal epithelial cell.
mesh_terms: D000328:Adult; D000584:Amiloride / Q000494:pharmacology*; D003864:Depression, Chemical; D004305:Dose-Response Relationship, Drug; D006801:Humans; D007413:Intestinal Mucosa / Q000502:physiology; D008297:Male; D008564:Membrane Potentials / Q000187:drug effects; D008722:Methods; D011719:Pyrazines / Q000494:pharmacology*; D012007:Rectum / Q000187:drug effects / Q000502:physiology*
chemical_list: D011719:Pyrazines; D000584:Amiloride