Inhibition by citrate of spontaneous precipitation of calcium oxalate in vitro

M. J. Nicar, K. Hill, C. Y. Pak

Research output: Contribution to journalArticlepeer-review

90 Scopus citations


Effect of citrate on the spontaneous precipitation of calcium oxalate was examined in synthetic media. Citrate significantly increased the formation product of calcium oxalate. This “direct” measure of inhibitor activity, representing activity product at the point of nucleation, rose by 76% by the addition of citrate sufficient to provide trivalent citrate concentration of 1.49 mM. Moreover, citrate inhibited calcium oxalate crystallization by complexing calcium and lowering calcium oxalate saturation. This “indirect” measure of inhibitor activity was assessed from the concentration product of calcium oxalate at the point of nucleation, since this measure should provide a reflection of both ion pair formation and direct inhibitor activity of citrate. The concentration product exceeded the formation product at all ionic (trivalent) citrate concentrations, particularly at high ionic citrate levels. At the ionic citrate concentration of 1.49 mM, the rise in the concentration product was 373%, which was nearly fivefold that observed for the formation product. The presence of ferric or aluminum cations at a physiologic concentration of 2 mg/l did not modify the increase in formation product produced by citrate. Thus, citrate inhibits calcium oxalate crystallization, largely by complexing citrate, but also by directly affecting nucleation. Presence of ferric or aluminum cations at a physiological concentration does not modify the inhibitor action of citrate.

Original languageEnglish (US)
Pages (from-to)215-220
Number of pages6
JournalJournal of Bone and Mineral Research
Issue number3
StatePublished - Jun 1987

ASJC Scopus subject areas

  • Endocrinology, Diabetes and Metabolism
  • Orthopedics and Sports Medicine


Dive into the research topics of 'Inhibition by citrate of spontaneous precipitation of calcium oxalate in vitro'. Together they form a unique fingerprint.

Cite this