Objective: The aim of the present study was to examine changes in locomotor activity during induction of hepatic encephalopathy in rats. We also examined plasma level of ammonia and serum levels of alkaline phosphatase, total protein, urea, and different forms of bilirubin after 28 days of obstruction of a common bile duct in rats as a model of hepatic encephalopathy. Methods: Male Wistar rats weighing 280-320 g were used. For induction of hepatic encephalopathy a common bile duct was transected but sham control operation consisted of laparotomy and bile duct identification without ligation and resection. On day of surgical laparotomy (day 1) before the surgery and also every 7 days after the surgery until day 28, the two experimental groups were examined for locomotor activity. On day 28 of the surgery, blood samples were collected from the heart of the animals, and plasma and serum were separated differently from blood sample of each rat for biochemical analysis. Results: The results of a two-way repeated measure ANOVA showed that locomotor activity was significantly decreased from day 7 after the bile duct ligation until day 28 of the surgery in rats with bile duct ligation compared to the sham control group during 28 days of the experiments. Biochemical analysis showed significant increases in plasma ammonia level as well as serum levels of total protein, urea, alkaline phosphatase and bilirubin in rats with bile duct ligation compared to the sham control group. Conclusion: According to the results of biochemical analysis and locomotor activity, it can be concluded that accumulation of toxic substances because of bile duct ligation induces chronic liver failure and hyperammonemia that in turn may lead to hepatic encephalopathy and hypokinesia.
