Effect of Diethylenetriaminepentaacetic Acid (DTPA) on Crystal Growth and Morphology of Calcium Oxalate

Muthulingam Nirmaladevi, Kumar Sanjiv Raj and Vadakkeputhanmadom Krishnayer Subramanian*

Effect of Diethylenetriaminepentaacetic Acid (DTPA) on Crystal Growth and Morphology of Calcium Oxalate

Deposition of stones in kidney is one of the most common and painful diseases particularly in
tropical regions. Various factors such as consumption of water, its quality, climate, lifestyle and
diet can affect the formation and type of kidney stone.

Majority of the kidney stones are composed of calcium, which may be in
the form of calcium oxalate (70-80%) or calcium phosphate
(10%) or mixture of both (40-50%).

However, calcium phosphate stone composition has been increasing steadily
for the past 30 years with female predominance. Apart from inorganic
composition, kidney stones may also contain organic matrix accounting for 2-5% of the total
stone weight.

Even though calcium oxalate exists in both monohydrate and dihydrate
crystal phases, several studies have reported that the precipitate in the urinary
tract consists of COM, having a greater stone forming tendency than COD
and that all papillary stones are COM stones.

The stone forming process is highly complex involving nucleation, crystal growth,
and aggregation of crystals in an environment containing supersaturated crystal-forming ions
(e.g. Ca2+, C2 O4 2−, PO4 3−, Mg2+, SO4 2−) in the presence of promoters and inhibitors.

The acid-rich urinary proteins suppress the crystallization of calcium oxalate even under supersaturated
conditions,11 thus preventing the formation of stones.

Chelation therapy is one of the recent techniques for the treatment of many
diseases including kidney stones.

Preferential crystallization of different forms of calcium oxalate has been
reported by many researchers by using certain synthetic and natural molecules,
such as polypeptides, sodium diisooctylsulfosuccinate, poly-block-poly,
renal epithelial cells,17,18 poly, biopolymeric additives,20 and protein
isolated from bean seed coats.

Nephrol Open J. 2017; 3(1): 1-8. doi: 10.17140/NPOJ-3-116