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Is citrate an inhibitor of calcium oxalate crystal growth in high concentrations of urine?

Abstract

The effect of citrate on calcium oxalate (CaOx) crystal growth was studied in a system in which series of samples containing [45Ca]calcium chloride were brought to different levels of supersaturation with various concentrations of oxalate. The crystallization was assessed by measuring the amount of isotope remaining in solution 30 min after the addition of CaOx seed crystals to samples containing citrate in concentrations corresponding to those in final urine. The experiments were carried out both in pure salt solutions and in solutions with dialysed urine. Increased concentrations of citrate resulted in a reduced crystallization of CaOx in both the presence and absence of dialysed urine, but with the lowest rate of crystallization in the samples containing urine. The increased concentration of 45Ca remaining in solution reflected a reduced crystallization, which could possibly be explained both by a reduced supersaturation and by an increased inhibition of CaOx crystal growth. The direct effects of citrate on CaOx crystal growth were assessed by calculating the ion-activity product of CaOx (APCaOx) at corresponding degrees of crystallization. The APCaOx recorded at a 30% reduction of the amount of isotope in solution increased with increasing concentrations of citrate between 1.0 and 1.5 mmol/l in samples both with and without dialysed urine. These findings indicate that citrate has a weak direct inhibitory effect on CaOx crystal growth, which adds to the reduced growth rate brought about by urinary macromolecules and a decreased supersaturation.

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References

  1. Angell AH, Resnick MI (1989) Surface interaction between glucosaminoglycans and calcium oxalate. J Urol 141:1255

    Google Scholar 

  2. Bek-Jensen H, Tiselius HG (1991) Inhibition of calcium oxalate crystallization by urinary macromolecules. Urol Res 19:165

    Google Scholar 

  3. Grases F, Costa-Bauza A (1990) Study of factors affecting calcium oxalate crystalline aggregation. Br J Urol 66:240

    Google Scholar 

  4. Grases F, Masárová L, Söhnel O, Costa-Banzá A (1992) Agglomeration of calcium oxalate monohydrate in synthetic urine. Br J Urol 70:240

    Google Scholar 

  5. Hess B (1992) Tamm-Horsfall glucoprotein-inhibitor or promoter of calcium oxalate monohydrate crystallization processes? Urol Res 20:83

    Google Scholar 

  6. Hess B, Nakagawa Y, Parks JH, Coc FL (1991) Molecular abnormality of Tamm-Horsfall glycoprotein in calcium oxalate nephrolithiasis. Am J Physiol 260:F569

    Google Scholar 

  7. Hess B, Zipperle L, Jaeger P (1993) Citrate and calcium effects on Tamm-Horsfall glycoprotein as a modifier of calcium oxalate crystal aggregation. Am J Physiol 265:F784

    Google Scholar 

  8. Kaiser ET, Bock SC (1989) Protein inhibitors of crystal growth. J Urol 141:750

    Google Scholar 

  9. Kok DJ, Papapoulos SE, Bijvoet OLM (1990) Crystal agglomeration is a major element in calcium oxalate urinary stone formation. Kidney Int 37:51

    Google Scholar 

  10. Minero C, Maggiorotti P, Barbeni M, Pelizzetti E, Tizzani A, Casetta G, Piana P, Giona C (1987) Effect of inhibitors on the crystal growth of calcium oxalate. Contr Nephrol 58:65

    Google Scholar 

  11. Ogawa Y (1994) Impact of sodium-potassium citrate on the diurnal variations in urinary calcium oxalate and calcium phosphate saturation levels in normal individuals. Br J Urol 73:136

    Google Scholar 

  12. Ryall RL, Marshall VR (1981) The effect of urine and other inhibitors on the growth and aggregation of calcium oxalate crystals in vitro. In: Urolithiasis (eds) Smith LH, Robertson WG, Finlayson B. Plenum Press, New York

    Google Scholar 

  13. Ryall RL, Marshall VR (1984) The relationship between urinary inhibitory activity and endogenous concentration of glucosaminoglycans and uric acid: comparison of urines from stone-formers and normal subjects. Clin Chim Acta 141:197

    Google Scholar 

  14. Sheinfeld J, Finlayson B, Reid F (1978) Ultrafiltration evidence of ion binding by macromolecules in urine. Invest Urol 15:462

    Google Scholar 

  15. Shirane Y, Kagawa S (1993) Scanning electron microscopic study of the effect of citrate and pyrophosphate on calcium oxalate crystal morphology. J Urol 150:1980

    Google Scholar 

  16. Tiselius HG (1985) Measurement of the risk of calcium oxalate crystallization in urine. Urol Res 3:297

    Google Scholar 

  17. Tiselius HG, Fornander AM (1981) Evaluation of a routine method for determination of calcium oxalate crystal growth inhibition in diluted urine samples. Clin Chem 27:565

    Google Scholar 

  18. Tiselius HG, Fornander AM, Nilsson MA (1987) Inhibition of calcium oxalate crystallization in urine. Urol Res 15:83

    Google Scholar 

  19. Tiselius HG, Fornander AM, Nilsson MA (1990) Effects of urinary macromolecules on the crystallization of calcium oxalate. Urol Res 18:381

    Google Scholar 

  20. Tiselius HG, Fornander AM, Nilsson MA (1993) The effects of citrate and urine on calcium oxalate crystal aggregation. Urol Res 21:363

    Google Scholar 

  21. Tiselius HG, Berg C, Fornander AM, Nilsson MA (1993) Effects of citrate on the different phases of calcium oxalate crystallization. Scan Microscopy 7(1):381

    Google Scholar 

  22. Tiselius HG, Fornander AM, Nilsson MA (1993) The effects of citrate and urine on calcium oxalate crystal aggregation. Urol Res 21:363

    Google Scholar 

  23. Wang YH, Grenabo L, Hedelin H, McLean RJC, Nickel JC, Pettersson S (1993) Citrate and urase-induced crystallization in synthetic and human urine. Urol Res 21:109

    Google Scholar 

  24. Werness PG, Brown CM, Smith LH, Finlayson B (1985) EQUIL2: a basic computer program for the calculation of urinary saturation. J Urol 134:1242

    Google Scholar 

  25. Yosihioka T, Koide T, Utsunomiya M, Itatani H, Oka T, Sonoda T (1989) Possible role of Tamm-Horsfall glycoprotein in calcium oxalate crystallization. Br J Urol 64:463

    Google Scholar 

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Bek-Jensen, H., Fornander, A.M., Nilsson, M.A. et al. Is citrate an inhibitor of calcium oxalate crystal growth in high concentrations of urine?. Urol. Res. 24, 67–71 (1996). https://doi.org/10.1007/BF00431081

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  • DOI: https://doi.org/10.1007/BF00431081

Key words

  • Calcium oxalate
  • CaOx crystallization
  • Crystal growth
  • Inhibition
  • Citrate
  • Dialysed urine