A Photomicroscopic Study on the Growth Rates of Calcium Oxalate Crystals in a New Synthetic Urine without Inhibitors and with Various Inhibitors

Yu-Chao Hsu,Lie-Ding Shiau,Li-Cheng Pan

doi:10.3390/cryst11030223

Abstract

A photomicroscopic growth apparatus was used to study the growth rates of calcium oxalate crystals in a new synthetic urine without inhibitors and with various inhibitors, including magnesium ions, citrate ions, chondroitin sulfate ions, and phytate ions. The dependence of growth rates on supersaturation at different temperatures without inhibitors was investigated using a power law model in terms of the Arrhenius form. The effects of various inhibitors on the growth rates of calcium oxalate indicated that the inhibition of growth rates increases in the order magnesium ions < citrate ions < chondroitin sulfate ions < phytate ions. The polymorphic forms of calcium oxalate crystals without inhibitors and with various inhibitors were examined by scanning electron microscopy.

Highlights

Renal stone disease is a common pathological disorder which affects about 10% of the global population [1]
The growth rates of calcium oxalate crystals in the new synthetic urine without inhibitors for the supersaturation of 10.09 to 18.01 in the range 32 ◦ C to 42 ◦ C were determined from the photomicroscopic growth experiments
The effects of various inhibitors on the mean growth rates of calcium oxalate crystals were compared for the supersaturation of 13.65 at 37 ◦ C

Summary

Introduction

Renal stone disease is a common pathological disorder which affects about 10% of the global population [1]. As COM has the strongest affinity for renal tubule cell membranes among the three hydrates, COM forms urinary stones; it is more difficult to eject out in urine than COT or COD [6]. The ease of calcium oxalate stone formation in urine depends on the degree of supersaturation, crystallization promoters, and crystallization inhibitors. The degree of supersaturation is generally dependent on the total concentrations of calcium ion and oxalate ion in the urinary solutions, respectively. Some studies indicated that different amino acids can both inhibit and promote the nucleation and crystallization of calcium oxalate depending on the acid structure [27,28]

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Results

Conclusion