Calcium oxalate crystal adherence in the rat bladder: restoration of anti-adherence after acid treatment.

PURPOSE

A role for the mucous lining of the urinary tract to prevent crystal adherence as well as the ability of glycosaminoglycans and other substances to restore anti-adherence after removal of the mucous lining was studied in the rat bladder.

MATERIALS AND METHODS

Following catheterization of the rat bladder a dilute solution of acid was introduced, which has been shown to remove the mucous lining. Sialic acid, hyaluronic acid, chondroitin sulfate, dermatan sulfate, heparin, pentosan polysulfate and urine were introduced into the bladder in an attempt to restore the anti-adherence properties removed by acid treatment. Radioactive calcium oxalate crystals were introduced into the bladder, followed by saline washes, and the crystals remaining were used as a measure of crystal adherence. Controls were mucous intact and acid treated bladders.

RESULTS

Hyaluronic acid, chondroitin-6-sulfate and chondroitin-4-sulfate did not influence adherence. Dermatan sulfate, heparin and pentosan polysulfate restored anti-adherence, while sialic acid and urine promoted adherence.

CONCLUSIONS

The mucous lining of the urinary tract serves as a defense against calcium oxalate crystal adherence. Dermatan sulfate decreases crystal adherence, whereas sialic acid promotes adherence. The balance between these 2 factors may have a role in stone formation.