Formation of Calcium Oxalates in the Human Body

Abstract

Urolithiasis is rather widespread disease. However, till now there are no reliable methods of treatment and preventive maintenance for this illness, despite significant efforts. Moreover, it is completely not clear how renal stones are forming. The majority of renal stones consist of calcium oxalates – monohydrated whewellite CaC₂O₄·H₂O and dihydrated weddellite CaC₂O₄·2H₂O. Weddellite is a metastable phase under crystallizing conditions, and usually its crystals are substituted with small-grained whewellite. At the same time, about 38% of oxalate renal stones are made of weddellite. The purpose of this work is to examine the influence of crystallizing conditions on the calcium oxalates phase formation in the renal stones. Our modeling experiments were carried out with the variation of crystallizing conditions (temperature, pH, proportion of calcium and oxalate, organic and inorganic species in the physiological solution, amount of micromycetes and bacterial–viral associates, and time of crystallization). Experimental data show that the presence of peptides, bacteria, micromycetes and viruses, Mg²⁺, and CO₃ ²⁻ ions in the solution stabilizes the calcium oxalate dehydrate crystallization.