Interaction of a complexing agent with urolith as the basis for efficient little-invasive therapy of phosphaturia

Autor: A. I. Strel’nikov, A. A. Shevyrin, Andrey V. Kustov, V. N. Trostin, Berezin Boris D
Rok vydání: 2009
Předmět:
Zdroj: Doklady Physical Chemistry. 428:175-177
ISSN: 1608-3121
0012-5016
DOI: 10.1134/s0012501609090048
Popis: The solubility of phosphate–oxalate urinary calculi in solutions of complexing agents was studied using a specially developed flow reactor at 37°C. The treat� ment of calculi 30–90 mg in weight for 2 h was found to significantly change the surface structure of the cal� culi and decrease the sample weight. The average sol� ubilities of uroliths in a solution of sodium citrate Na 3 Cit (5%, pH 8.6), a citrate buffer solution (pH 6.4), and a solution of sodium ethylenediaminetetraacetate Na 2 H 2 EDTA (pH 4.6) are 17.5 ± 4, 35.2 ± 3, and 54.2 ± 8 wt %, respectively. Based on the results obtained, developed litholysis methods of residual concrements are proposed. Urolithiasis is a widespread disorder all over the world, affecting no less than 5–10% of population. More than 70% of calculi are made of calcium oxalate and calcium phosphate or their mixtures [1–3]. In this connection, no wonder that a wide circle of researches are interested in understanding mecha� nisms of stone formation, inhibiting stone deposition, and determining the conditions for spontaneous dis� charge of concrements [3–7]. In particular, citrate and ethylenediaminetetraacetate anions were shown [6, 7] to be inhibitors of deposition due to formation of complexes with Ca 2+ ion [8]. Citrate ions excreted in urine are precisely the species, which play this role in organism [4, 5]. In the present work, we studied in vitro interaction of aqueous solutions of chelating agents with phos� phate–oxalate calculi in order to develop a quantita� tive experimental base for chelation therapy. EXPERIMENTAL Reagents Na2H2EDTA (more than 99%, Che� mapol) and Na 3 Cit (more than 99%, Panreac) were used without additional purification. The reagents were dried in vacuum at 80°C to constant weight. The weighed salt samples were dissolved in appropriate vol� umes of bidistilled water. A citrate buffer (pH 6.4) was prepared by a standard procedure [9]. Phosphate– oxalate stones were obtained after surgical procedures (pyelolithotomy or ureterolithotomy) at Ivanovo State
Databáze: OpenAIRE
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