Toxic Effects and Depuration on the Antioxidant and Neurotransmitter Responses after Dietary Lead Exposure in Starry Flounder.

Abstract

Starry Flounder Platichthys stellatus were exposed to dietary lead (Pb) at concentrations of 0, 30, 60, 120, and 240mg/kg for 4weeks. Recover period was conducted for 2weeks after the exposure. Exposure to Pb concentrations over 60mg/kg induced significant changes in the antioxidant responses in the liver, kidney, and gill and continued even after the depuration period in the liver (over 120mg/kg for superoxide dismutase [SOD] activity) and kidney (at 240mg/kg for glutathione [GSH] levels). Glutathione S-transferase (GST) activity in liver, kidney, and gill were increased by dietary Pb exposure, and recovery was observed in all groups during the recovery period. Acetylcholinesterase (AChE) activity was significantly inhibited in the brain and muscle of flounder at Pb exposure over 120mg/kg, and no restoration was observed after the depuration period. Lysozyme activity in the plasma was significantly increased at Pb exposures greater than 60mg kg but was restored after the depuration period. The results of this study indicate that dietary Pb exposure induces toxic effects on antioxidant responses, neurotransmitter, and immune responses of Starry Flounder.