Brain oxidative stress induced by obstructive jaundice in rats.

The effect of experimental obstructive jaundice on the oxidative status of brain tissues in rats was examined. Twenty-four male Wistar rats were divided into 4 groups: Group I was the control, group II was the sham operated, and groups III and IV were bile duct ligated and killed on the 5th and the 10th day, respectively. Oxidative stress was assessed by measuring the thiol redox state (protein and nonprotein components) and lipid peroxidation level variations in samples from the cerebral cortex, midbrain, and cerebellar tissue in all animals. Results indicated the presence of oxidative stress in the jaundiced animals that was more pronounced on the 10th day as indicated by a decrease in reduced glutathione and protein thiol and an increase in protein disulphide and lipid peroxidation. A dramatic elevation of the level of total nonprotein mixed disulphide level was found specifically in the midbrain in the 10th day group. This suggests an accumulation of nonprotein disulfides other than oxidized glutathione, which remained unchanged, in this particular brain area. This study showed a correlation between experimental obstructive jaundice and the oxidative stress in the rats' brain, implying that a similar pathogenetic mechanism may play a key role in cholestatic liver disease, resulting in hepatic encephalopathy in humans.