Effect of Glycochenodeoxycholic Acid on Unidirectional Transepithelial Fluxes of Electrolytes in the Perfused Human Ileum

Abstract

Perfusion studies of the terminal ileum were performed in healthy volunteers to define the influence of a dihydroxy bile acid, glycochenodeoxycholic acid (GCDC) 2.5 mmol/1, on the mechanisms of electrolyte transport. Net movements of water and electrolytes, bidirectional fluxes of sodium, potassium, and chloride, and the transmural electrical potential difference (PD) were measured simultaneously. The results supported the notion of an active mechanism for sodium and chloride transfer. GCDC evoked net secretion of water and electrolytes, and decreased the mucosa to serosa flux of chloride. There was a tendency that the latter also applied to sodium and potassium. During bile acid perfusion active secretion of chloride occurred. PD was 16±4 mV, lumen negative, and was not influenced by GCDC. In conclusion, we propose a model for the GCDC effect.

Key-words:

• Absorption
• intestinal
• bile acids
• biological transport, active
• cell membrane permeability
• electrolytes
• membrane potentials
• perfusion
• water movement