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Nucleation of calcium oxalate crystals by albumin: involvement in the prevention of stone formation.
Kidney Int. 1999 May; 55(5):1776-86.KI

Abstract

BACKGROUND

Urine is supersaturated in calcium oxalate, which means that it will contain calcium oxalate crystals that form spontaneously. Their size must be controlled to prevent retention in ducts and the eventual development of a lithiasis. This is achieved, in part, by specific inhibitors of crystal growth. We investigated whether promoters of crystal nucleation could also participate in that control, because for the same amount of salt that will precipitate from a supersaturated solution, increasing the number of crystals will decrease their average size and facilitate their elimination.

METHODS

Albumin was purified from commercial sources and from the urine of healthy subjects or idiopathic calcium stone formers. Its aggregation properties were characterized by biophysical and biochemical techniques. Albumin was then either attached to several supports or left free in solution and incubated in a metastable solution of calcium oxalate. Kinetics of calcium oxalate crystallization were determined by turbidimetry. The nature and efficiency of nucleation were measured by examining the type and number of neoformed crystals.

RESULTS

Albumin, one of the most abundant proteins in urine, was a powerful nucleator of calcium oxalate crystals in vitro, with the polymers being more active than monomers. In addition, nucleation by albumin apparently led exclusively to the formation of calcium oxalate dihydrate crystals, whereas calcium oxalate monohydrate crystals were formed in the absence of albumin. An analysis of calcium oxalate crystals in urine showed that the dihydrate form was present in healthy subjects and stone formers, whereas the monohydrate, which is thermodynamically more stable and constitutes the core of most calcium oxalate stones, was present in stone formers only. Finally, urinary albumin purified from healthy subjects contained significantly more polymers and was a stronger promoter of calcium oxalate nucleation than albumin from idiopathic calcium stone formers.

CONCLUSIONS

Promotion by albumin of calcium oxalate crystallization with specific formation of the dihydrate form might be protective, because with rapid nucleation of small crystals, the saturation levels fall; thus, larger crystal formation and aggregation with subsequent stone formation may be prevented. We believe that albumin may be an important factor of urine stability.

Authors+Show Affiliations

INSERM U315, Physiologie et Pathologie Digestives, Hôpital Sainte-Marguerite, Marseille, France.No affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

10231440

Citation

Cerini, C, et al. "Nucleation of Calcium Oxalate Crystals By Albumin: Involvement in the Prevention of Stone Formation." Kidney International, vol. 55, no. 5, 1999, pp. 1776-86.
Cerini C, Geider S, Dussol B, et al. Nucleation of calcium oxalate crystals by albumin: involvement in the prevention of stone formation. Kidney Int. 1999;55(5):1776-86.
Cerini, C., Geider, S., Dussol, B., Hennequin, C., Daudon, M., Veesler, S., Nitsche, S., Boistelle, R., Berthézène, P., Dupuy, P., Vazi, A., Berland, Y., Dagorn, J. C., & Verdier, J. M. (1999). Nucleation of calcium oxalate crystals by albumin: involvement in the prevention of stone formation. Kidney International, 55(5), 1776-86.
Cerini C, et al. Nucleation of Calcium Oxalate Crystals By Albumin: Involvement in the Prevention of Stone Formation. Kidney Int. 1999;55(5):1776-86. PubMed PMID: 10231440.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Nucleation of calcium oxalate crystals by albumin: involvement in the prevention of stone formation. AU - Cerini,C, AU - Geider,S, AU - Dussol,B, AU - Hennequin,C, AU - Daudon,M, AU - Veesler,S, AU - Nitsche,S, AU - Boistelle,R, AU - Berthézène,P, AU - Dupuy,P, AU - Vazi,A, AU - Berland,Y, AU - Dagorn,J C, AU - Verdier,J M, PY - 1999/5/7/pubmed PY - 1999/5/7/medline PY - 1999/5/7/entrez SP - 1776 EP - 86 JF - Kidney international JO - Kidney Int VL - 55 IS - 5 N2 - BACKGROUND: Urine is supersaturated in calcium oxalate, which means that it will contain calcium oxalate crystals that form spontaneously. Their size must be controlled to prevent retention in ducts and the eventual development of a lithiasis. This is achieved, in part, by specific inhibitors of crystal growth. We investigated whether promoters of crystal nucleation could also participate in that control, because for the same amount of salt that will precipitate from a supersaturated solution, increasing the number of crystals will decrease their average size and facilitate their elimination. METHODS: Albumin was purified from commercial sources and from the urine of healthy subjects or idiopathic calcium stone formers. Its aggregation properties were characterized by biophysical and biochemical techniques. Albumin was then either attached to several supports or left free in solution and incubated in a metastable solution of calcium oxalate. Kinetics of calcium oxalate crystallization were determined by turbidimetry. The nature and efficiency of nucleation were measured by examining the type and number of neoformed crystals. RESULTS: Albumin, one of the most abundant proteins in urine, was a powerful nucleator of calcium oxalate crystals in vitro, with the polymers being more active than monomers. In addition, nucleation by albumin apparently led exclusively to the formation of calcium oxalate dihydrate crystals, whereas calcium oxalate monohydrate crystals were formed in the absence of albumin. An analysis of calcium oxalate crystals in urine showed that the dihydrate form was present in healthy subjects and stone formers, whereas the monohydrate, which is thermodynamically more stable and constitutes the core of most calcium oxalate stones, was present in stone formers only. Finally, urinary albumin purified from healthy subjects contained significantly more polymers and was a stronger promoter of calcium oxalate nucleation than albumin from idiopathic calcium stone formers. CONCLUSIONS: Promotion by albumin of calcium oxalate crystallization with specific formation of the dihydrate form might be protective, because with rapid nucleation of small crystals, the saturation levels fall; thus, larger crystal formation and aggregation with subsequent stone formation may be prevented. We believe that albumin may be an important factor of urine stability. SN - 0085-2538 UR - https://www.unboundmedicine.com/medline/citation/10231440/Nucleation_of_calcium_oxalate_crystals_by_albumin:_involvement_in_the_prevention_of_stone_formation_ L2 - https://linkinghub.elsevier.com/retrieve/pii/S0085-2538(15)46133-2 DB - PRIME DP - Unbound Medicine ER -