Effect of Combined Administration of Tryptophan with Putative Tryptophan Pyrrolase Inhibitors, DL-3-Pyridylalanine, Allopurinol or Nicotinamide, on Brain Serotonin Concentration

概要

論文の詳細を見る
1) Single administration of tryptophan (25-200 mg / kg) to Wistar male rats resulted in a dose-related increase in liver tryptophan pyrrolase (TP) activity. The increase in brain serotonin (5-HT) concentration was not proportional to the dose given, and brain 5-HT concentration rapidly fell to the control (saline-treated) level or below. 2) The tryptophan-induced increase in liver TP activity was clearly prevented by DL-3-pyridylalanine (3-PA, 100 mg/kg). Serum free tryptophan and brain 5-HT concentrations increased more markedly and maintained higher levels after the combined administration of tryptophan with 3-PA than after a single administration of tryptophan. 3) Although allopurinol (20 mg/kg) reduced liver TP activity under control and tryptophan-treated conditions, it did not increase serum free tryptophan and brain 5-HT concentrations. 4) Nicotinamide also failed to alter the catabolism of tryptophan and the concentration of brain 5-HT in control or tryptophan-treated rats. 5) These data suggest that 3-PA would increase the therapeutic effect of tryptophan given to treat depressive illness, but that allopurinol and nicotinamide would not be suitable drugs for this purpose.
公益社団法人日本薬学会の論文
1984-06-25