Glial changes in pigs with porto-caval anastomosis and temporary or total hepatic artery clamping.

The number and size of astrocyte, oligodendrocyte, and neurone nuclie were determined in cortex and corpus striatum (putamen) of pigs with porto-caval anastomosis (PCA) and total or temporary clamping of the hepatic artery. Animals with PCA and total clamping became comatose and died on average 18 1/2 hours postoperatively. Their brains showed slight oedema but no changes in the glial and neurone nuclear numbers. Animals with PCA and temporary clamping of the hepatic artery (30-60 min.) all survived without clinical symptoms of encephalopathy. However, the brains showed vacuolization of the deeper cortical layers, diffuse occurrence of Alzheimer type II astrocytes, and the counts revealed an increased number of astrocytic nuclei. The total number of glial cells decreased due to loss of oligodendrocytes, but the number of neurones was unchanged. The findings indicate that the neuropathological changes after PCA and temporary hepatic artery clamping are concerned primarily with changes of the glial cells.