Abstract
Protein malnutrition produced marked elevations in brain contents of histamine in guinea pigs (+142%) and rats (+257%) in comparison with findings in the control adequately fed animals. Associated with accumulation of this biogenic amine in each set of animals was an increase of similar magnitude in brain content of free histidine. It was concluded that the elevated brain content of histamine in protein malnutrition was due mainly to increased availability of the precursor amino acid, and that such alterations in amounts of neurotransmitter amines in the central nervous system might underlie some of the behavioural abnormalities seen in malnourished animals.