Orally Administered Melatonin and the Accumulation and Toxicity of Cadmium in the Bank Vole (Myodes Glareolus)

Abstract

Orally Administered Melatonin and the Accumulation and Toxicity of Cadmium in the Bank Vole (Myodes Glareolus)Animal gender and age significantly influence the accumulation and toxicity of heavy metals, including cadmium (Cd). The aim of this study was to determine the effect of orally administered melatonin (6 μg/ml), a known antioxidant and metal chelator, on Cd accumulation and toxicity in one month old females and males (young) and five months old bank voles (old) exposed to dietary Cd (100 μg/g) for six weeks. Compared to the Cd alone group, melatonin co-treatment brought about a decrease of Cd concentration in the liver (17% and 20%) and kidneys (39% and 36%) of young female and male bank voles, respectively, while in old animals increased Cd accumulation in liver (65%) and kidneys (81%) and enhanced consumption of Cd-contaminated food (136%) without any effect on their body mass. The results suggest that orally administered melatonin together with cadmium in young bank voles reduces tissue Cd accumulation possibly through forming stable complexes with this metal but in older rodents, melatonin increases concentration of the metal through increasing consumption of Cd-contaminated food.