Changes in Total Protein and Transaminase Activities of Grass Carp Exposed to Diquat

Total protein in plasma and muscle of grass carp Ctenopharyngodon idella was significantly lower (P < 0.05) in fish exposed to 53.0 mg diquat/L than in fish exposed to 2.0 mg diquat/L. Generally, total protein in fish exposed to 2.0 mg diquat/L was not significantly different from total protein in control fish (0.0 mg diquat/L) throughout 168 h of exposure. Aspartate aminotransferase (=glutamic-oxaloacetic transaminase; GOT) activities increased significantly in plasma, muscle, and liver of fish exposed to 53.0 mg diquat/L. However, in fish exposed to 2.0 mg diquat/L, plasma and liver GOT decreased significantly. Alanine aminotransferase (=glutamicpyruvic transaminase; GPT) activities increased significantly in plasma and liver of fish exposed to 53.0 mg diquat/L, whereas there was no change in fish exposed to 2.0 mg diquat/L.