Water Movement Across the Cecal Wall of the Germfree Rat 1

Abstract

Summary

The present experiments demonstrate that the isotonic saline absorption of cecal sacs in vivo is significantly larger in germfree than in conventionally-raised rats living on the same diet. The osmotic permeability of the cecal wall, on the other hand, is not statistically different in the two groups under the experimental in vivo conditions employed. While other findings are compatible with the assumption that the retention of water in the cecal lumen of the intact germfree animal is due to the presence of osmotically active substances to which the cecal mucosa is impermeable, the sodium-coupled water transport seems to be increased as a compensatory mechanism.