A model for transepithelial fluid transport

A number of experimental observations which are not easily, or at all, accommodated within the framework of the natriocentric theory for transepithelial fluid transport are discussed. These are shown to be not merely accommodated but actually predicted by a simple model for fluid transport in which the major osmotic force leading to fluid transport derives from solutes other than NaCl. The model is then analyzed for feasibility in light of existing data relating to reflection coefficients for NaCl and hydraulic conductivity. Certain lines of evidence for specific active sodium transport are critically reexamined.