%0 Journal Article
%T Stabilization of Submicron Calcium Oxalate Suspension by Chondroitin Sulfate C May Be an Efficient Protection from Stone Formation
%A Jun-Jun Li
%A Jun-Fa Xue
%A Jian-Ming Ouyang
%J Bioinorganic Chemistry and Applications
%D 2013
%I Hindawi Publishing Corporation
%R 10.1155/2013/360142
%X The influences of chondroitin sulfate C (C6S) on size, aggregation, sedimentation, and Zeta potential of sub-micron calcium oxalate monohydrate (COM) and calcium oxalate dihydrate (COD) crystallites with mean sizes of about 330£¿nm were investigated using an X-ray diffractometer, nanoparticle size Zeta potential analyzer, ultraviolet spectrophotometer, and scanning electron microscope, after which the results were compared with those of micron-grade crystals. C6S inhibited the conversion of COD to COM and the aggregation of COM and COD crystallitesis; it also decreased their sedimentation rate, thus increasing their stability in aqueous solution. The smaller the size of the COD crystallites, the easier they can be converted to COM. The stability of sub-micron COD was worse than that of micron-grade crystals. C6S can inhibit the formation of calcium oxalate stones. 1. Introduction The formation of urinary stones is closely related to supersaturation, nucleation, growth, and aggregation of stone salt. Compared with the urine of stone patients, normal urine has more types of inhibitors with higher concentration and stronger activity. These inhibitors include some small-molecule inorganic salts such as citrate and pyrophosphate and urinary macromolecules such as glycosaminoglycan (GAG), nephrocalcin, Tamm-Horsfall protein, and prothrombin fragment 1 [1¨C5]. As the main component of urinary stones, calcium oxalate (CaOxa) mainly exists in the form of calcium oxalate monohydrate (COM) and calcium oxalate dehydrate (COD). In the urine of patients afflicted with urinary stones, the existing probability of COM crystallites is much higher than that in healthy controls [6]. A study showed that CaOxa crystals in urine only take 3£¿min to 4£¿min to flow through the nephron [7] and about 12£¿min to pass through the pelvis. Within such a short time, the crystal could not grow into a pathological size (larger than tens of microns). Rapid aggregation of the crystals is an important factor in CaOxa stone formation [8, 9]. GAG is an important urinary macromolecule that inhibits urinary stone formation [2]. Urinary GAGs originate from two sources. The first source of urinary GAGs is the serum, which is filtered through the kidney into the urine. The electrophoretic types of GAGs in urine are similar to those present in the serum; moreover, the excretion of urinary GAGs increases along with the increment of GAG concentration in the serum [10¨C12]. The GAGs in the serum originate from degradation products of proteoglycans in connective tissues, such as the cartilage,
%U http://www.hindawi.com/journals/bca/2013/360142/