Nucleation kinetics in the calcium oxalate-sodium urate monohydrate system.

The nucleation kinetics of calcium oxalate were studied in the presence and absence of sodium urate monohydrate crystalline material by three experimental measurements. These included analytical determinations of calcium and radiotracer analysis of oxalate in the metastable calcium oxalate solution phase and the independent detection of new crystal nuclei by solution turbidity measurements. None of the methods gave any evidence that sodium urate increases the induction time for nucleation of calcium oxalate, in contrast to previously published reports. These results are discussed in relation to the mechanisms advanced to explain the interdependency of hyperuricosuria and calcium oxalate urolithiasis.