Abstract
Summary
A study of the differential effects of excess dietary L-phenylalanine, L-tyrosine, L-valine, and phenylacetic acid on serotonin content of rat brain and liver indicated that phenylalanine is the most effective of these compounds. Five and 7% L-phenylalanine caused a decrease mainly in the brain. Seven percent tyrosine caused little or no change. Brain serotonin decreased when 6% L-valine was fed and brain and liver serotonin decreased when valine was included as 9% of the diet. Most of the change in liver serotonin is due to decreased food intake, since paired-fed control rats also showed decreased serotonin in this tissue. Phenylacetic acid caused an increase in brain serotonin, an effect opposite to that of phenylalanine or valine.
Get full access to this article
View all access options for this article.