Simulation On Inhibition Of Calcium Oxalate Calculus Grown In The Presence Of Various Carboxylic Acids In Gel Systems

According to the periodicity of urinary calculus precipitation, a double diffusion technique (U-tube method) was adopted. In the sodium silicate hydrogels systems., we investigated the inhibition of the carboxylic acid and phosphate on CaOxa crystallization. The inhibit mechanism was discussed also.1. Crystallization of calcium oxalate (CaOxa) was comparatively investigated in five gel systems in the absence and presence of Kacit. The five gelatinous systems are water, sodium chloride, synthesized urine, diluted healthy urine and diluted pathological urine. In the absence of K3cit, calcium oxalate monohydrate (COM) is the dominant phase. However, calcium oxalate dihydrate (COD) and trihydrate (COT) crystals appeared simultaneously in the gel systems from sodium chloride and synthesized urine systems. COD appeared also in the diluted pathological urine, whereas the size of the CaOxa crystals in the diluted healthy urine becomes much smaller obviously. In the presence of K3cit, the percentage of COT increased markedly in the gel systems from water, sodium chloride and synthesized urine. A great deal of COD appeared in the diluted pathological urine system, and a few COD andCOT appeared in the diluted healthy urine system.2. Effect of various counterions of tartrate on the crystallization of CaOxa was investigated. The considered tartrates include hydrogen (Hatart), sodium (Na2tart), potassium (K2tart), ammonium ((NH4)2tart), and a mixture of sodium and potassium cations (NaKtart). For H2tart, Na2tart, and (NH4)2tart, COD was induced. However, COT were obtained for K2tart and NaKtart. The ability of tartrates to induce COD and COT increased as increasing their concentration, respectively. The temperature affects the phase and morphology of CaOxa crystals. COM and COT were obtained at 37癈, but COD was dominant below 7.3. Supersaturation could effect the phase, morphology and aggregation of CaOxa crystals. Oxa2" ions have stronger effect on the aggregation of CaOxa than Ca2+ ions. High ionic strength promote the aggregation of CaOxa crystals.4. The effect of various kinds of phosphates on the morphology and phase compositions of CaOxa crystals was investigated. The ability to induce COD and to decrease the surface area of COM increased in the order: Na3PO4 < Na4P2O7 < Na5P3O10. This ability increased with the increase of their concentrations. When the concentration was 40 mmol/L, about 6%,25% and 40% of COD was induced, respectively. Na4P2O7 makes the angles of COM crystals become round, and Na5P3O10 makes the angles of COM disappeared. The capacity of phosphates to induce COD and decrease the surface area of COM was in favor of the prevention and cure of urinary stones.5.Animal experiments. Based on the animal models of calcium oxalate stones induced by glycol, the ability of different carboxylates to decrease the content of calcium and oxalate in the urine and kidney of mice in the order: K2EDTA K3cit K2tart KAc. This result is in correspondence with the simulation in vitro.