Comparison of Growth Kinetic of Urinary Crystallites from Patients with Calcium Oxalate Stones with that from Healthy Subjects

Abstract

The differences of growth kinetic of urinary crystallites from patients with CaOxa stones and healthy subjects were compared. With the increase of crystal growth time (t), the size of urinary crystallites from patients increased constantly from 10±9 μm att=1 h to 50±45 μm att=72 h, but the number of urinary crystallites decreased gradually from 1820±610 ind./mm2att=1 h to 220±98 ind./mm2att=72 h, indicating that the formation process of crystallites in lithogenic urine was ascribed to growth control. In contrast, for healthy subjects, the number of crystallites increased from 1650±850 ind./mm2att=1 h to 1800±830 ind./mm2att=72 h. However, the particle size was slowly increased from 7±5 μm att=1 h to 14±13 μm att=72 h, while the sizes of most urinary crystallites were still less than 20 μm, indicating that the growth process of crystallites in healthy urine was dominated by nucleation control. The differences mentioned above are mainly attributed to that both the concentration and the activity of the inhibitors in healthy urine were higher than those in lithogenic urine, and the inhibitors in healthy urine can inhibit the growth and aggregation of urinary crystallites more effectively. This result can help to elucidate the renal-calculi formation mechanism.