초록
This study was performed to investigate effect of dietary protein and calcium levels on cad-mium intoxication in rats. Adult Sprague-Dawley male rate(245$\pm$21g) were blocked into 18 groups of 7 animals according to body weight Nine experimental diets different with protein(40%, 15%, 7%) and calcium (1.3%, 0.6%, 0.1%) levels were prepared. Nine groups of animals were fed each diet with 50ppm cadmium in drinking water and the other 9 groups without cadmium for 30days. Results were summarized as follows: 1) Body weight gain F. E. R(Food Efficiency Ratio) and weights of liver kidney and femur were higher in high protein groups among cadmium exposed groups. 2) Cadmium contents in liver and intestine were higher in rats fed high protein diet or low calcium diet among cadmium exposed groups. Fecal cadmium excretion was highest in high protein-high calcium diet group among cadmium exposed animals. Metallothionein contents in liver kidney and intestine were higher in animals exposed to cadmium and fed high protein diets. 3) Gel filtration chromatography of cytosolic solution showed that the higher dietary protein and calcium levels were the more cadmium was found in metallothionein fractions. 4) No gross histopathological change was seen in liver kidney and intestine of cadmium exposed rats. However a significant increase of smooth endoplasmic reticulum which was alleveated by high protein-high calcium diet was observed. Results obtained indicated that not only high protein diet but also high calcium diet showed preventive effect on cadmium intoxication by increasing the induction of metallothionein syn-thesis and decreasing the cadmium absorption.
