Responses of Labeo rohita fingerlings to N-acetyl-p-aminophenol toxicity

The short term (96 h) toxicity of N-acetyl-p-aminophenol (0.58 mg/L - Treatment I and 0.29 mg/L - Treatment II) on certain health indicators (haematology, biochemical, and enzymology) of an Indian major carp Labeo rohita was studied. When compared to control, N-acetyl-p-aminophenol treated fish showed a significant (P < 0.05) decrease in haemoglobin (Hb), haematocrit (Hct), and erythrocyte (RBC) levels throughout the study period. Whereas, a significant (P < 0.05) increase were noted in leucocyte (WBC) counts (except 48 h in Treatment-I), mean corpuscular volume (MCV), and mean corpuscular haemoglobin (MCH) values (except 24 h in Treatment-I). Mean corpuscular haemoglobin concentration (MCHC) values were found to be decreased significantly (P < 0.05) in fish exposed to 0.58 mg/L of N-acetyl-p-aminophenol, whereas in 0.29 mg/L exposed fish the values were found to be increased significantly (P < 0.05) (except 72 h). A significant (P < 0.05) increase in plasma glucose levels was noticed in fish exposed to 0.58 mg/L of N-acetyl-p-aminophenol (except 96 h). However, a biphasic trend in plasma glucose level was observed at 0.29 mg/L of N-acetyl-p-aminophenol exposed fish. Protein levels were found to be increased in both the treatments except at the end of 48 and 96 h in 0.58 and 0.29 mg/L, respectively. In both the treatments fluctuations of enzyme (GOT, GPT, and LDH) activities in gill and liver were also noted. However, these enzyme activities found to be significantly (P < 0.05) decreased in kidney and plasma of fish. From the result we conclude that the drug N-acetyl-p-aminophenol upon short term exposure could pose a risk to fish and the alteration of these parameters can be used to ecological risk assessment of pharmaceuticals in aquatic organisms.