ACCUMULATION OF CADMIUM FROM WHEAT BRAN, SUGAR-BEET FIBER, CARROTS AND CADMIUM CHLORIDE IN THE LIVER AND KIDNEYS OF MICE

The gastrointestinal absorption and organ distribution of Cd after exp osure for 9 weeks to three fibre-rich foodstuffs (wheat bran, sugar-be et fibre and carrots) were determined in mice. Groups of eight mice we re given a diet containing 0.05 mg Cd/kg from wheat bran, sugar-beet f ibre, carrots or CdCl2 mixed in a semi-synthetic, low-Cd (<0.007 mg/kg ) feed. A control group was fed on the low-Cd semi-synthetic feed. The water consumption, food consumption and the weight of the animals wer e monitored throughout the study. The feed was changed once weekly and Cd was analysed in the feed at each change. myo-Inositol phosphates ( hexa-, penta-, tetra- and tri-) and Zn, Cu, Fe and Ca were also analys ed in the diets. After 9 weeks, the mice were killed and liver and kid neys were sampled and analysed for Cd. The group receiving the wheat-b ran diet had significantly lower fractional Cd accumulation (% total C d intake) in the liver and kidneys than the other groups, indicating a lower fractional absorption of Cd. The wheat-bran diet had markedly h igher levels of inositol hexa- and pentaphosphates (phytates) and a Zn level that was twice as high as those in the other diets. The higher levels of myo-inositol hexa- and pentaphosphates in the wheat-bran die t most probably contributed more to the lower fractional absorption of Cd than the elevated Zn level, due to the formation of insoluble Cd-p hytate complexes. Compared with the wheat-bran diet, the sugar-beet-fi bre and carrot diets contained very low levels of myo-inositol penta- and hexaphosphates, and consequently the fractional Cd absorption from these diets was higher.