Relative Liver Weight in Rats Subacutely Exposed to Polychlorinated Biphenyls

Abstract

Polychlorinated biphenyls (PCBs) are pollutants abundantly present in the environment. Before they were banned, commercial mixtures of PCBs had been produced in many countries and were used for a number of technical purposes. This is considered to be the main source of the current levels of PCBs found in the environment due to their lipophilic properties and high persistence. The aim of this study was to evaluate dose-response relationship for the effects of the commercial PCBs mixture on relative liver weight by Benchmark dose (BMD) approach, and to derive the BMD10 for the effect. In this study, commercial mixture of PCBs, Aroclor 1254 was used in a 28-day toxicity study in young adult Wistar rats. The rats were provided with food and water ad libitum and maintained in a controlled environment. Commercial mixture of PCBs dissolved in corn oil or corn oil (control) was administered by oral gavage at 1 μL/g. Rats were given doses of 0.5, 1, 2, 4, 8, 16 mg PCBs/kg b.w./day. After 28 days rats were sacrificed and their livers were weighted. Relative liver weight was calculated as ratio of liver weight and body weight. Using PROAST software a dose-response relationship has been confirmed for the influence of PCBs on relative liver weight and associated CED10 was 0.154 mg/kg bw/day, and its lower confidence limit (CEDL) was 0.1127 mg/kg bw/day proving CED10/CEDL ratio under 10. Our results showed that relatively low doses of PCBs may produce effect on liver weight causing liver hypertrophy in a dose response manner.