On the possible role of glycosaminoglycans as natural inhibitors of calcium oxalate stones.

An extract of glycosaminoglycans was prepared from normal urine and components fractionated by electrophoresis on Vinylite support medium. Several fractions displayed an ability to inhibit formation of calcium oxalate crystals in vitro. Inasmuch as well recognized urinary glycosaminoglycans such as chondroitin sulfates and hyaluronic acid must contribute to the urine inhibitory power, an unknown material was isolated with potent inhibitory properties. The material contained little detectable uronic acid of hexosamine and had a molecular weight greater than 10,000.