Na, Cl, and Water Transport by Rat Ileum <i>in Vitro </i>

TLDR

In an in vitro rat ileum preparation, the interrelationship between metabolism, NaCl transport, and water transport has been investigated and discussed within a model system. Glucose in the mucosal solution drives active Na⁺ and Cl⁻ transport from mucosa to serosa, with water absorption passively following net solute movement; removing glucose or inhibiting metabolism blocks salt transport and consequently reduces water absorption, indicating water uptake depends on active salt transport.

Abstract

Interrelationships between metabolism, NaCl transport, and water transport have been studied in an in vitro preparation of rat ileum. When glucose is present in the mucosal solution, Na and Cl both appear to be actively transported from mucosa to serosa while water absorption is passive and dependent on net solute transport. Removal of glucose from the mucosal solution or treatment with dinitrophenol, monoiodoacetate, or anoxia inhibits active salt transport and as a result, water absorption is also inhibited. The dependence of water absorption on metabolism can be explained as a secondary effect due to its dependence on active salt transport. The relationship between salt and water transport has been discussed in terms of a model system.