Urea transport across dog intestinal mucosa in vitro

Abstract

Mucosal membranes from the small intestine of the dog were stripped and mounted for study between two bathing fluids, as previously described. The relationship between urea and water transport, including uphill movement of urea in the direction of water flow, was that expected from a combination of bulk flow and diffusion. If sieving was present, it was minor. Results for downhill movement of D₂O, the isotopic water treated as a solute, were comparable to those for urea.