[Frontiers in Bioscience 12, 2580-2587, January 1, 2007]

Phytate acts as an inhibitor in formation of renal calculi

Felix Grases1, Bernat Isern1, Pilar Sanchis1, Joan Perello1, Jose Juan Torres2, Antonia Costa-Bauza1

1 Laboratory of Renal Lithiasis Research, University Institute of Health Sciences Research (IUNICS), University of Balearic Islands, Palma of Mallorca, Spain, 2 University Hospital Son Dureta, Palma of Mallorca, Spain


1. Abstract
2. Introduction
3. Materials and methods
3.1. In vivo studies
3.1.1. Animals, diets and treatments
3.1.2. Phytate containing cream pre-treatment
3.1.3. Induction of calcinosis, monitorization and sample acquisition
3.1.4. Histological analysis
3.1.5. Quantitation of phytate
3.1.6. Calcium determination
3.1.7. Statistics
3.2. In vitro studies
3.2.1. Synthetic urine
3.2.2. Effects of phytate
4. Results and Discussion
4.1. In vivo studies
4.2. In vitro studies
5. Discussion
6. Acknowledgements
7. References


The aim of this study was to assess the inhibitory action of phytate in formation of renal calculi. Hypertension (induced by nicotine) combined with hypercalcemia (induced by D vitamin) was used to induce calcification in renal tissue in male Wistar rats that were fed a purified phytate free diet. Phytate non-treated rats developed significant calcium deposits in kidneys and papillae, as well as in kidney tubules and vessels, whereas calcium deposits were absent in control and phytate treated rats. Fragments of hydroxyapatite (HAP) calculi exhibited the capacity to induce the growth of calcium salts on their surfaces. Presence of 1.5 mg/L of phytate in the synthetic urine inhibited the formation of calcium oxalate monohydrate on HAP renal calculi in normocalciuric conditions. The findings show that the action of phytate as a crystallization inhibitor takes place both in the intrapapillary tissue and urine.