[The role of renal acid mucopolysaccharides in the mechanism of reabsorption of osmotically free water].

The authors compared the histochemical characteristics of acid mucopolysaccharides (MPS) of the medulla of the kidney with functional indices of the latter in dogs under conditions of water, osmotic diuresis and in polyuria caused by the administration of heparin. There was seen a correlation between the changes in the MPS staining and the intensity of reabsorption of osmotically free water. On the basis of the results obtained a supposition was put forward that the change in the physico-chemical properties of the MPS served as one of the most significant factors determining the permeability of the medulla structures for the passage of water from the tubular lumina into the interstitium.