The Effect of Ammonia Infusion on Brain Monoamine Metabolism in Portacaval-Shunted Rats*

The effect of ammonia infusion on monoamine metabolism was studied in the rat brain. Seven days after portacaval shunt (PCS) or sham operation animals were infused with ammonia or saline. Brain metabolism of serotonin and norepinephrine was studied after injection of a decarboxylase inhibitor (m-hydroxybenzylhydrazine, NSD 1015) which blocks the conversion of 5-hydroxytryptophan to serotonin and dihydroxyphenylalanine to dopamine. Neurologic testing was conducted before killing. Plasma and brain amino acids were measured.