Biochemical and histologic presentations of female wistar rats administered with different doses of paracetamol/methionine

Summary: This study was carried out to compare the hepatoprotective effect of methionine on paracetamol treated rats at both the peaks of toxicity and absorption. Female Wistar rats were divided into 17 groups consisting of eight rats per group and treated with different doses of paracetamol/methionine (5:1). Each control rat received 5 ml of physiologic saline. The study was terminated at two different end points –the 4^th & 16^th hours. Results show that rats administered with toxic doses (1000 mg/kg; 3000 mg/kg; 5000 mg/kg BW) of paracetamol exhibited significant increases (p<0.05) in the levels of ALT, AST, γ- GT compared with controls. These increases were much higher at the 16^th than 4^th hour but serum total protein, albumin and globulin were significantly decreased (p<0.05) by the end of the 16^th hour. Histology results of rats in the 3000 & 5000 mg/kg (by the end of the 16th hour) confirmed hepatic damage; light microscopic evaluation of liver showed remarkable centrilobular necrosis. Moreover, the presence of mononuclear cells in liver section of rats intoxicated with APAP (5000 mg/kg) suggests a possible involvement of inflammatory process which resulted in regurgitation of bilirubin leading to its elevated level as well as increase activity of ALP. The hepatoprotective effect of methionine, on the other hand, was demonstrated in these rats at the 4^th & 16^th hours, and both results were comparable and therefore not significantly different (p>0.05) but elevation in GGT level still persisted. In conclusion, data obtained from this study suggest that these agents may be capable of inducing GGT, although further study is required to establish a possible relationship between methionine and this enzyme in some other animal species.