Transmucosal potential-difference profile in rat upper gastrointestinal tract. A simple model for testing gastric effects of pharmacologic agents

Transmucosal potential difference in the rat upper gastrointestinal tract is described by a simple in vivo technique. Values for potential difference between blood (reference) and lumen (in millivolts) were the following: esophagus, −13.7 ± 1.6 (mean ± SE); forestomach (rumen), −39.2 ± 0.8; stomach fundus, −39.1 ± 0.4; pylorus, −26.6 ± 0.6; and duodenum, −9.2 ± 0.4. These values (excluding rumen) are strikingly similar to those obtained in man. Aspirin, taurocholic acid, and alcohol all produced falls in gastric potential difference very similar to those found in man. The rat appears to be a promising and convenient model for screening gastric effects of certain pharmacological agents before use in man.