Tissue-specific recovery of oxidative and antioxidant effects of chlorpyrifos in the freshwater crab, Barytelphusa guerini.

Chlorpyrifos (CPF), an organophosphate widely applied in agriculture and aquaculture, induces oxidative stress due to free-radical generation and changes in the antioxidant defense system. The present study investigated the short-term effect of CPF exposure on the oxidative and antioxidant systems and their recovery responses in metabolically active tissues (gills, hepatopancreas [HP], and leg muscle) of freshwater crab Barytelphusa guerini. Crabs were exposed to a sublethal concentration of CPF (0.07 mg L(-1)) for a total of 8 days (at intervals of 1, 2, 4, and 8 days) in clean water. The following oxidative stress markers were measured: acetylcholinesterase (AChE), butylcholinesterase (BChE), and ATPase; antioxidants i.e., superoxide dismutase (SOD), catalase, and glutathione reductase (GR), lipid peroxidation (LPO), conjugating enzyme glutathione S-transferase (GST), glutathione peroxidase (GPx), and lipid content. CPF exposure led to a significant decrease in the activity of oxidative stress markers as follows: AChE (84 %), BChE (46 %), and gills Na(+)/K(+) ATPase (62 %). At the end of the recovery period, enzyme levels were recovered except in leg muscle. Total lipids and SOD decreased; CAT and LPO levels increased; and GPx, GR, and GST showed tissue-specific activities. Maximum recovery was observed in GPx followed by GR in HP tissue of crab. Nevertheless, these responses apparently grant successful adaptation for survival in a pesticide-extreme environment.