Crystallization theory relating to urinary stone formation

Abstract

Although little is known at the present time about the factors which control the nucleation of pathological concretions, the growth of such solid phases in biological fluids such as urines must be mediated by physical chemical principles governing the kinetics of crystallization. Elucidation of the mechanism of the precipitation processes may be complicated by the difficulty in defining the degree of supersaturation in these biological systems but a great deal can be learned from in vitro crystal growth kinetic studies. In this paper, the physical chemical principles which govern the nucleation and growth of sparingly soluble salts in aqueous media are discussed as they relate to urinary stone formation. In vivo, the number of mineral phases which is involved is relatively small and the results for two important salt systems, the calcium phosphates and calcium oxalates are discussed in the light of recent kinetics studies in which the supersaturation is maintained constant during crystallization experiments.