Hepatic and Renal Toxicity of Methamidophos in Male Domestic Rabbit

Abstract

Objective: The present study is aimed to investigate hepatic and renal toxicity of methamidophos in male domestic rabbit. Materials and Methods: The oral LD50 of methamidophos in male domestic rabbit was calculated and found to be 20.5 mg kg-1 body weight. The daily dose of 1/10 LD50 methamidophos (2.1 mg kg-1 body weight) was given orally to 36 animals under experiment for six weeks. Thirty six control animals were given distilled water. Blood samples were collected weekly and analyzed. Results: The overall mortality rate was 11.1% in methamidophos-treated rabbits compared to 0.0% in controls. Clinical signs included diarrhea, disorientation, drowsiness, weakness, depression and mild tremors. The final body weight was significantly decreased in methamidophos-intoxicated rabbits. Serum glucose was significantly increased in response to methamidophos administration recording a maximum percentage difference of 27.1% in the 4th week of the experiment. The activities of alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP) and gamma glutamyl transferase (γ-GT) were significantly higher in methamidophos-fed rabbits compared to controls, registering maximum percentage differences of 31.2, 44.7, 26.7 and 45.6% during the 6th, 4th, 4th and 3rd weeks of the experiment. In contrast, serum cholinesterase (ChE) was significantly decreased recording a maximum percentage difference of 77.8% at the end of the experiment. Serum bilirubin was gradually increased to record a maximum percentage difference of 19.3% in the 5th week. Serum urea and creatinine concentrations were significantly elevated in response to methamidophos intake displaying maximum percentage differences of 45.8% and 31.7% during the 4th week of the experiment. Serum total protein, albumin and globulin were significantly decreased upon methamidophos intoxication exhibiting percentage differences of 27.0, 25.9 and 24.3% at 5th week of the experiment. Serum calcium was significantly decreased in methamidophos-treated rabbits with a maximum percentage difference of 17.4% at the end of the experiment, whereas phosphorus was significantly increased with a maximum percentage difference of 23.8% at the 4th week of the experiment. Conclusions: Oral daily administration of 1/10 LD50 methamidophos caused significant decrease in the body weight, serum cholinesterase, total protein, albumin, globulin and calcium whereas serum glucose, ALT, AST, ALP, g-GT, bilirubin, urea, creatinine and phosphorus were significantly increased.