Brain monoamines after portacaval anastomosis.

Norepinephrine, dopamine, and serotonin, as well as the serotonin metabolite, 5-hydroxyindoleacetic acid, were measured in whole-brain extracts from rats with a portacaval shunt or sham operation. Norepinephrine, serotonin, and 5-hydroxyindoleacetic acid were significantly higher after shunting. There was no difference in dopamine. The results support the idea that brain indole metabolism is increased during chronic hepatic encephalopathy. However, they provide evidence against suggestions that hepatic encephalopathy in general is accompanied by a shortage in the whole-brain content of the catecholamines norepinephrine and dopamine.