EFFECTS OF CALCIUM CHELATING AGENTS AND ACID MUCOPOLYSACCHARIDES ON THE GROWTH OF CALCIUM OXALATE DIHYDRATE CRYSTALS

Abstract

Effects of calcium chelating agents (Na₃-citrate, 4Na-ethylenediaminetetraacetic acid, adenosin triphosphate; final concentration 1mM), acid mucopolysaccharides (chondroitin sulfate A, B, C heparan sulfate; final concentration 1×10^-3%), pyrophosphoric acid (1mM), MgCl₂ (1mM) and normal urine (1%) on the growth of calcium oxalate dihydrate crystals were studied in crystallisation medium. In order to avoid the transformation of calcium oxalate dihydrate to a monohydrate, experiments were performed at 6°C, in a 24hr incubation. The size and the number of crystals were analized by a Particle Size Distribution Analizer. The apparent inhibitory effect on the growth of crystals was observed in chondroitin sulfate B, heparan sulfate and normal urine. Calcium chelating agents also showed an inhibitory effect. However, pyrophosphoric acid had a promotive effect.