World J Nephrol Urol

World Journal of Nephrology and Urology, ISSN 1927-1239 print, 1927-1247 online, Open Access

Article copyright, the authors; Journal compilation copyright, World J Nephrol Urol and Elmer Press Inc

Journal website http://www.wjnu.org

Original Article

Volume 4, Number 1, March 2015, pages 173-177

Arginine as a Significant Regulator of Supersaturation in Calcium Oxalate Lithiasis: the Physiological Evidence

Figure

Figure 1. Solubility of calcium oxalate calculi in artificial urine as a function of L-arginine concentration. Solubility in zero saturation urine (curve 1). Solubility in artificial urine with lower saturation (curve 2). Solubility in artificial urine with normal saturation (curve 3).

Tables

**Table 1.** Serum Levels and Urine Excretions of Amino Acid Arginine in the Patients With a Calcium Oxalate Calculosis and Control Group [13]
	Ref. value [13]	Controls (n = 15)	Stone formers (n = 56)
Arginine, x (μmol/L) (in serum)	49.7 - 132.1 (Male) 46.9 - 139.7 (Female)	94.7 ± 54.5	109.9 ± 39.4
Arginine, x (μmol/24 h) (in urine)	7 - 47	-	-

**Table 2.** L-Arginine as a Solvent of Calcium Oxalate: Comparison With Classical Complex Forming Agents [8, 14, 16]
Ligand	Complex former	Solution	T (°C)	pH	K_i (L/mol)	Reference
C₂O₄^2-	Mg²⁺	0.3 M NaCl	25	5.0	4.0 × 10³	[8]
C₂O₄^2-	Mg²⁺	0.3 M NaCl	37	-	5.6 × 10³	[14]
Na-EDTA	Ca²⁺	Physiological solution	25	7.0	5.0 × 10⁵	[14]
Citric anion	Ca²⁺	Pure water	25	-	5.0 × 10²	[16]
L-arginine	Ca²⁺	0-artificial urine	25	5.4	5.6 × 10³	Fig. 1