Solubility and dissolution kinetics of calcium oxalate renal calculi in solutions, containing DL-lysine: in vitro experiments

An analysis of dissolution of slightly soluble salts in physiological solut ions in the presence of complexing ions was carried out, simulating conditi ons typical in human urine. It was found that DL-lysine, a normal physiolog ical constituent of urine, acts at increased concentrations as a dissolving agent with respect to calcium oxalate (CaOX) calculi. The kinetics of diss olution of crystalline CaOX calculi in physiological solutions containing D L-lysine at different concentrations were studied, using the change in the Archimedean weight of samples immersed in the solution. The possible effect of lysine as a natural regulator of CaOX supersaturation and crystallizati on in human urine is also discussed. (C) 2000 Elsevier Science B.V. All rig hts reserved.