Related Experiment Videos
Reduced crystallization inhibition by urine from men with nephrolithiasis
J R Asplin1, J H Parks, M S Chen
1Renal Section, Department of Medicine, University of Chicago, Illinois 60637, USA.
Kidney International
|October 3, 1999
Summary
Men with calcium oxalate stones exhibit reduced urine stone inhibitors. This impaired inhibition, affecting crystal growth and limits of metastability, may promote kidney stone formation.
Area of Science:
- Nephrology
- Biochemistry
- Urology
Background:
- Human urine normally inhibits calcium oxalate monohydrate (COM) crystal formation, a key component of kidney stones.
- Reduced inhibition in urine may contribute to the development of kidney stones.
Purpose of the Study:
- To test if men with calcium oxalate stones have lower urine inhibition levels.
- To investigate the role of urine proteins in COM crystal growth and aggregation.
Main Methods:
- Compared urine protein inhibition of COM growth and aggregation in 17 stone-forming men and 17 controls.
- Assessed whole urine upper limits of metastability (ULM) for COM and calcium phosphate (CaP) relative to supersaturation (SS).
- Studied COM crystal binding to cultured renal cells.
Main Results:
- Stone-forming men showed reduced COM growth inhibition and lower ULM relative to SS compared to controls.
- 15 out of 17 patients displayed abnormalities in at least one inhibition measurement.
- Defects in ULM and growth inhibition often occurred together.
Conclusions:
- Reduced COM growth inhibition and lower ULM values are characteristic of male kidney stone formers.
- These defects can promote kidney stone nucleation and growth.
- Impaired urine inhibition is a significant factor in human nephrolithiasis.