The effect of long-term high heavy metal intake on lipid peroxidation of gastrointestinal tissue in sheep

Abstract

The present study was designed to determine the effects of dietary heavy metal intake on malondialdehyde levels (MDA, product of cellular lipid peroxidation) in the tissues of gastrointestinal tract, kidneys and liver of sheep. The experiment was carried out on twelve female sheep of mixed breed, weighing from 30 to 35 kg, one year old. The first group of sheep was bred in the conditions of laboratory farm. They had free access to hay and 300 g of barley per sheep was added daily. The second group grazed on a natural pasture in the environs of a factory processing copper ore. The second group of sheep had significantly higher concentrations of copper and cadmium in the tissues of rumen wall, duodenum, colon wall, liver and kidneys. The concentration of lead was significantly higher in the rumen wall, colon, liver and kidneys, but no differences were found in duodenum. The concentration of mercury was significantly higher only in the kidney tissue, but no differences were found in rumen wall, duodenum, colon wall and liver. The concentration of malondialdehyde was found significantly higher in reticulum epithelium, omasum, duodenum and colon. The significantly higher concentration of MDA was measured in colon wall and kidney medulla. The highest concentration of MDA was found in liver. Our results confirm that lipid peroxidation is one of the molecular mechanisms of cell injury in chronic heavy metal poisoning. The epithelium of the gastrointestinal tract of sheep is more sensitive to the oxidative damage induced by dietary heavy metal intake.