Stimulation of NGF production by tryptophan and its metabolites in cultured mouse astroglial cells.

Effects of various amino acids and tryptophan metabolites on the synthesis of nerve growth factor (NGF) in cultured mouse astroglial cells were evaluated. L-Tryptophan stimulated NGF production in a dose-dependent manner. Serotonin and quinolinic acid slightly increased NGF synthesis. L-Kynurenine had a marked stimulatory effect on NGF production at a dose of 10 microM. In contrast, kynurenic acid had no effect on the reaction. L-Glutamine, L-glutamic acid, L-phenylalanine and L-methionine produced no significant change in NGF synthesis. These results were discussed in relation to the treatment of Alzheimer's diseases.