Effects of carbenoxolone on gastric mucosal permeability and blood flow in the dog.

The effects of topical application of carbenoxolone at neutral and acidic pH were compared in exteriorized, chambered segments of canine gastric corpus. When dissolved in saline at pH 7.5 to 8.0, 0.25% carbenoxolone caused a rapid drop in gastric potential difference of 56 +/- 2 mv and greatly increased permeability to H+ ions. Blood flow, as measured by radioactive microspheres, was not changed by carbenoxolone treatment, but subsequent exposure to isotonic HC1 caused an abrupt rise in flow. Application of 0.25% carbenoxolone suspension in isotonic HC1 caused no change in potential difference, permeability, or blood flow. Neither carbenoxolone preparation had a significant effect on aspirin-induced H+ back-diffusion or injury.