[Antagonism of the ammonia effect on serotonin receptors by L-valine]

Ammonia and valine influence the activity of serotonin receptors in membranes of frontal cortex taken from brain removed at postmortem: Ammonia reduces maximal binding capacity of serotonin receptors, and this effect can be antagonized by valine. This modulatory effect of valine seems to be efficient at a lower level in tissues of patients with hepatic coma. Branched chain amino acids may have efficient therapeutic effects in hepatic coma due firstly to effects on the blood brain barrier by a well known mechanism of action and secondly to molecular interaction at the synaptic membrane.