Short- and long-term effects of copper on the rosy barb (Puntius conchonius Ham.)

The rosy barb (Puntius conchonius) was exposed to copper (Cu) for short (48 hr) and long (8 weeks) terms and effects on enzyme activities and biochemical variables in the blood and tissues were examined. In vivo exposure to 571 micrograms CuSO4/liter (96-hr median tolerance limit (TLm)) for 48 hr stimulated to varying degrees acid phosphatase (AcP), alkaline phosphatase (AlP) (except in the liver), and acetylcholinesterase activities in selected tissues. The alanine aminotransferase and lactic dehydrogenase (LDH) (except in the heart) activities were inhibited to varying degrees in vivo. In vitro, the presence of 10(-6) M Cu suppressed enzyme activities in the tissues examined, with a few exceptions such as AcP in ovaries and gut, AlP in liver, gills, gut, and testes, and LDH in liver. Hyperglycemia, hyperlactemia, hyperproteinemia, elevated blood free fatty acid (FFA) levels, and hypocholesterolemia were manifested in the fish exposed to 190 micrograms CuSO4/liter (1/3 96-hr TLm). Effects on the tissues included glycogenolysis (liver and skeletal muscles), glycogenesis (brain and heart), a marked rise in hepatic proteins, accumulation of FFAs in liver and skeletal muscles, and reduction in hepatic and gonadal cholesterol contents. After 8 weeks, a trend toward recovery was noted in the biochemical variables (except blood and hepatic protein levels).