A Quantitative Investigation of the Effects on the Growth of Calcium Oxalate Crystals on Potential Inhibitors

Abstract

CALCIUM OXALATE is one of the most common constitutents of renal calculi. The presence of this compound in the nucleus of most calcium-containing stones and the discovery by Hodgkinson (1969) that the smaller the stone the greater the proportion of calcium oxalate, have encouraged the idea that calcium oxalate may be an important factor in the initiation of renal stones. As calcium oxalate crystals are easily produced in vitro, a number of investigators have designed experiments to study the formation of these crystals and the effect of various substances on their growth rate. Lyon and Vermeulen (1965) grew oxalate crystals on wire loops suspended in water or a simple salt solution by the slow diffusion of calcium and oxalate ions through filter paper wicks into the media. Some compounds, considered to be potential inhibitors of crystal growth, were added to the media and the crystals examined after a number of days. Using a similar method, Sutor (1969) examined the effects on calcium oxalate growth of a wide variety of substances using an acetate buffer. A further paper by Sutor and Wooley (1970) examined the action of other compounds in the acetate buffer and also in human urine. In all these experiments the crystals were allowed to grow for approximately 1 week and then studied by simple observation. However, this method of assessment is subjective and not in any way quantitative. In this paper, a method is described for the estimation of crystal growth by measuring the calcium content of crystals. Substances which might be expected to inhibit calcium oxalate growth were added to acetate buffer and human urine. Their effects on the formation of crystals over a 24-hour period were studied.

Role of Urinary Zinc and Copper on Calcium Oxalate Stone Formation

“…Moreover, serum Zn levels were low in stone formers. Other authors, however, detected no differences relating to Zn and Cu urinary excretion between healthy controls and stone formers [4][5][6]. Finally, in our stoneforming group, we found significantly higher amounts of urinary Zn compared to the healthy group, but there is no significant difference in urinary Cu excretion between the 2 groups.…”

“…In vitro trials demonstrated inhibitory as well as stimulating influences of individual inorganic ions on the crystallization process [5,10]. There are many studies showing that calcium oxalate crystals, one of the most common constituents of renal calculi, are easily produced in in vitro trials.…”

Analysis of the Trace Element Contents of Inner Nucleus and Outer Crust Parts of Urinary Calculi

“…We then supposed that the determination of lead, cadmium, nickel, and aluminum contents of inner nucleus and outer crust parts of various kinds of urinary calculi might give useful information to reach a decision on whether some trace elements, including essential and toxic ones, play a part in the disease or not. Suggestions that some trace elements tend to enhance the growth rate of deposits of crystalline calcium compounds and thus may play a part in influencing, causing, accelerating, or inhibiting the precipiation of urinary tract calculi [7][8][9] make the elucidation of these and other related subjects significant.…”

A Review of Pathological Biomineral Analysis Techniques and Classification Schemes

“…The most widely practiced chemical analysis, however, are those aimed at identifying not only major elements but minor and trace ones (Trinchieri et al, 2005;Moe, 2006;Atakan et al, 2007;Bazin et al, 2007;Joost & Tessadri, 1987;Meyer & Angino, 1977;Munoz & Valiente, 2005;Sutor, 1969;Welshman & McGeown, 1972). The latter may have played a significant role in urinary stone nucleation and growth, or may be considered as environmental pollution markers (ATSDR, 2008;Bernard, 2008;IPCS, 1992;Jarup, 2002;Patrick, 2003;Satarug et al, 2010).…”