Phytic acid-induced metabolic changes in the rat.

Phytic acid (PA) is present in considerable amounts in the seeds of many plant species consumed by animals. Little is known about its influence on metabolic processes. In the performed experiment the effect of rats feeding a standard laboratory diet (Murigran) with increasing supplements of PA on some hormones and biochemical parameters was tested. Male Wistar rats were divided into five groups of eight animals each. In the first group (control) rats were fed a diet without any supplement whereas the groups II-V received food with added PA: 0.1, 0.2, 0.3 and 1%. After 20 days animals were decapitated, blood serum, liver and tight muscles were sampled. In rats fed a diet enriched in PA the concentration of thyroid hormones was diminished. Simultaneously, T(3)/T(4) ratio was slightly reduced. These changes were accompanied by a rise in blood glucose level and an augmentation in liver and muscle glycogen stores and were found in spite of unchanged blood insulin. Consumption of food with increased amounts of PA resulted in a substantial reduction of liver triglyceride content, but serum triglycerides were not affected. In rats from groups II and III serum free-fatty acids concentration was reduced. However, in animals receiving highest PA supplement this effect was not observed. Serum calcium and magnesium were not affected by PA. Serum iron was significantly reduced, but only in rats on the highest supplement of the tested compound. Results obtained in this experiment clearly indicate that the PA is able to induce hormonal and metabolic changes in animals. These changes seem to result not only from reduced bioavailability of minerals but also from interactions of PA with nutrients and enzymes in the liver.