Effect of cadmium on enzymatic digestion and sugar transport in the small intestine of rabbit

Abstract

Cadmium compounds are found widely in our environment: for example, in food, water, soil, and ambient air. The most important exposure route of animals to cadmium in the general environment is via oral exposure. In oral cadmium intoxication, the immediate target organ is the gastrointestinal tract. The aim of the present work was to determine how cadmium acts on the intestinal absorption of sugars and on the sucrase activity through rabbit jejunum, after in vitro administration and/or oral administration of CdCl₂ in drinking water. Results obtained show that cadmium decreasesD-galactose accumulation in the jejunum tissue. This effect seems to be the result of an action mainly located on Na⁺-dependent sugar transport of the mucosal border of the intestinal epithelium, because cadmium seemnnot to modify the sugar diffusion across the intestinal epithelium. Cadmium has also been shown to inhibit the (Na⁺-K⁺)-ATPase activity of the enterocyte, which might explain the inhibition of theD-galactose Na⁺-dependent transport. Nevertheless, a direct action of the cadmium molecule on the Na⁺-dependent carrier cannot be discarded. Cadmium altered the sucrose activity when it was administered in the drinking water for 4 d.