Disturbances in the permeability of the cerebral blood vessels in the experimental hepatic encephalopathy

The purpose of this study was to determine the permeability of brain vessels in experimental hepatic encephalopathy. The experiments were carried out with 30 experimental and 21 control white Wistar rats.In the experimental group liver cirrhosis was induced by subcutaneous injection of CC14 in liquid paraffin. The control group was treated with liquid paraffin. All animals were given 1-5% silver nitrate as marker of the permeability of brain vessels.Fatty degeneration of the liver was observed after 2 months of experiment, liver cirrhosis after 4 and 6 months. In the animals of the 2-month group there were slight glial abnormalities in the brain characteristic of hepatic encephalopathy. Its full morphological picture was observed in animals killed after 4 and 6 months. In this period there also appeared lesions bearing evidence of increased permeability of the cerebral vessels for silver salts. The barrier remained impermeable for Evans blue-coupled albumin. These facts seem to indicate the selective damage of barrier mechanisms for silver salts. They remained normal for high molecular weight substances. The fact that glial alteration precedes the appearance of silver in the cerebral parenchyma suggests the role of degenerated glia in the production of the disturbances of barrier mechanisms. In turn, the increased vascular permeability can augment the gliopathy.