Simulation of Chronic Intoxication in Rats Exposed to Cadmium and Mercury

Abstract

Cadmium and mercury are widespread and non-biodegradable pollutants of great concern to human and animal health. In this study, the influence of exposure to low doses of cadmium and mercury on Wistar rats was investigated. The experiments aimed to identify suitable markers of chronic intoxication with heavy metals in rats. The subjects were 48 naive young rats (24 females and 24 males), four weeks old, grouped randomly into three distinct groups—control group, group exposed to cadmium and group exposed to mercury. The control group received sham treatment—clean untreated water. Cd exposed group received water containing cadmium chloride dihydrate and Hg exposed group received water with mercury dichloride. Both cadmium and mercury were administered to experimental rats in drinking water in concentrations exceeding the maximum acceptable concentration of these metals 500 times, i.e., 0.5 mg Hg and 2.5 mg Cd per liter of water. The results were evaluated quarterly during the experiment (52 weeks). Selected physiological parameters (life span, body weight changes and intake of food and water), reproductive parameters (number of births (litters), number of born pups and number of raised pups) and toxicological parameters (average daily dose, total dose received and the amount of toxic metal received) were studied. The results of the experiments indicate differences between both individual groups and between males and females, which confirmed that these parameters are essential in such experiments of chronic exposure to subtoxic doses of heavy metals.