[Effect of urinary material and glycosaminoglycans on calcium oxalate monohydrate crystal aggregation]

We have examined by the coulter counter method whether some substances promote or inhibit calcium oxalate monohydrate crystal aggregation. The substances tested were hyaluronic acid, chondroitin sulfate and urinary lyophilized material of less than 10 k dalton fractions having aggregate activity. As a result, hyaluronic acid promoted aggregation at low concentrations but inhibited it at higher concentrations, and chondroitin sulfate only inhibited it. They seem, therefore, to have quite different effects, depending on their urinary concentrations, on calcium oxalate crystal aggregation process. However, urinary fractions only promoted aggregation in a dose-response manner. This promoting effect might be caused by not only hyaluronic acid that was contained in the fractions but also by some other promoters.