Temperature affects Hg-induced antioxidant responses in Chinese rare minnow Gobiocypris rarus larvae in vitro.

Abstract

The effect of temperature on HgCl2 (Hg(2+))-induced oxidative stress to Chinese rare minnow (Gobiocypris rarus) was evaluated in vitro. Malondialdehyde (MDA) content and superoxide dismutase, catalase and glutathione peroxidase activities were determined in whole body homogenates incubated with 0.1 mg/L Hg(2+) at 15, 25 and 35°C for 60 min. The result showed that oxidative stress was at a normal level in the Hg(2+) + NT (0.1 mg/L Hg(2+) and normal temperature, 25°C) and Hg(2+) + LT (0.1 mg/L Hg(2+) and low temperature, 15°C) groups, but a significant induction in oxidative stress occurred in the Hg(2+) + HT (35°C) group. This was reflected by an increased level of MDA and decreased activities of the antioxidant enzymes. The results suggest that higher temperature enhances heavy metal toxicity in aquatic systems, which should be given more attention in the future.