Study of factors affecting calcium oxalate crystalline aggregation

A study was made of the effects of citrate, pentosan polysulphate (a glycosaminoglycan) and mucin (a mucoprotein) upon crystalline growth and aggregation of calcium oxalate in synthetic urine. It was found that citrate inhibited aggregation. Pentosan polysulphate had no perceptible effect on aggregation but favoured the formation of calcium oxalate dihydrate crystals. Mucin enhanced the formation of large characteristic aggregates and also led to the formation of calcium oxalate dihydrate crystals. Particles of mucin in a solution served as a substrate on which several crystals of calcium oxalate dihydrate were formed by heterogeneous nucleation; the subsequent growth of these crystals resulted in the formation of large agglomerates.