[Effect of cellulose on iron, zinc and copper metabolism in growing rats]

The purpose of the study was determination of the effect of cellulose on the apparent absorption and tissue concentrations of iron, zinc and copper in growing rats. Male Wistar rats with initial body weight 108 +/- 2 g were fed during 6 weeks isocaloric diets containing 1%, 5% or 10% of dietary fibre. The diets contained about 18% protein (casein and wheat gluten 1:1) and iron 28 mg, zinc 17 mg and copper 4.5 mg per kg of diet. In the 2nd, 4th and 6th weeks of the experiment feaces were collected during 2 days. Mineral components of the diets, cases liver, spleen, kidneys and femur were determined by atomic absorption spectrophotometry. No significant differences were noted in diet intake or in body weight gain between these groups. Increased cellulose content in diet, that is 5% or 10%, reduced significantly the absolute and per cent apparent absorption of copper and its concentration in liver, which indirectly led to disturbances of iron metabolism. As a result, the concentration of haemoglobin was reduced and the hepatic iron reserve was raised. No adverse effect of cellulose was found on the apparent absorption of iron and zinc and on zinc concentration in the studied tissues. The per cent coefficients of apparent absorption of iron decreased during the experiment, while those of zinc and copper increased.