This study was undertaken to investigate how the permeability of the blood brain barrier (BBB) changed in the rats with liver failure. In the experimental group, 50 rats were injected with carbon tetrachloride (CCl4) s.c. three times a week for six weeks. CCl4 was dissolved in olive oil (3/4 v/v).

Twenty rats were injected with olive oil s.c. for control group. When characteristic findings of hepatic encephalopathy occurred, evans-blue (%2) was given by jugular vein at a dose of 4 ml/kg under ether anesthesia. Five minutes later, rats were killed by intracardiac injection of saline. Cerebrum and cerebellum were removed and evaluated visually and spectrophotometrically. The concentration of evans-blue in the brain tissues of the experimental group was higher than that of control (p<0.0005). There was a significant difference betwen cirrhotic rats with hepatic encephalopathy and cirrhotic rats without hepatic encephalopathy in the levels of brain evans-blue (p<0.005).

In conclusion, we suggest that hepatic encephalopathy increases the BBB permeability in the rat.