Crystal Growth and Aggregation of Calcium Oxalate in High Ionic Strength Solutions
According to the hyperexcretion-supersaturation theory1, the concentrations of ions in urines of calcium oxalate stone formers persistently exceed the formation product of this salt, and, as a consequence, calcium oxalate crystals are produced by spontaneous nucleation, growth and aggregation. Some of the crystals, or aggregates, are eventually trapped in the kidney and become the nidus for a stone. It has been proposed2,3 that urines of normal individuals contain inhibitors of crystal growth and aggregation which are decreased or absent in stone formers. Accordingly, much effort has been spent to test potential inhibitors, but most models permit only the measurement of an overall effect, without separating the two precipitation processes. In this study a model system is presented by which the kinetics of crystal growth and aggregation can be followed subsequently and independently in systems in which both processes proceed simultaneously. Quantitative estimates of the rates of crystal growth and aggregation of calcium oxalate from high ionic strength solutions, such as prevail in crystalluria, are given. The proposed model makes it possible to study the effect of inhibitors on both processes simultaneously and independently in the course of spontaneous precipitation.
KeywordsCrystal Growth Calcium Oxalate Kinetic Experiment Coulter Counter Calcium Oxalate Crystal
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