Abstract
The effects of chelating agents, such as citric acid, ethylendediaminetetraacetic acid (EDTA), L-cysteine and L-leucine, on the inhibition of small intestinal absorption of L-histidine with cadmium in rats were studied. The depressed absorption of L-histidine (1.29 mM) from the small intestine of rats in situ in the presence of cadmium (0.27 mM) was greately restored by the addition of citric acid (10-20 mM) and EDTA (0.5 mM), and moderately by L-cysteine (1.29 mM). In addition, the intestinal accumulation of cadmium was significantly decreased by the addition of citric acid, EDTA and L-cysteine. An in vitro intestinal experiment suggested that the result of complexing of cadmium by the chelating agents, such as citric acid, EDTA and L-cysteine, decreased the accumulation of cadmium in the intestinal tissue and protected the active transport of L-histidine across the rat small intestine.
