Metabolism of D-phenylalanine and its effects on concentrations of brain monoamines and amino acids in rats--a basic study on possibility of clinical use of D-phenylalanine as an antidepressant.
The effect of D-phenylalanine on the concentrations of brain catecholamines, serotonin, beta-phenylethylamine and amino acids was examined using rats injected intraperitoneally with 200 mg/kg of D-phenylalanine. The contents of these monoamines in the rat brain were not affected by the administration of D-phenylalanine. No spectacular change was observed in the concentrations of brain amino acids except phenylalanine, which increased about four times during 30-60 minutes after the injection. This increase was attributed to the administered D-phenylalanine. To confirm the finding that D-phenylalanine did not affect the content of beta-phenylethylamine, the metabolism of D-phenylalanine was examined using D-[14C]-phenylalanine. It was proven that D-phenylalanine did not convert to beta-phenylethylamine. On the basis of these findings the antidepressant effect of D-phenylalanine was critically discussed.
D000596:Amino Acids / Q000032:analysis; D000818:Animals; D001679:Biogenic Amines / Q000032:analysis*; D001923:Brain Chemistry / Q000187:drug effects*; D004298:Dopamine / Q000032:analysis; D008297:Male; D009638:Norepinephrine / Q000032:analysis; D010627:Phenethylamines / Q000032:analysis; D010649:Phenylalanine / Q000378:metabolism / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D012701:Serotonin / Q000032:analysis
D000596:Amino Acids; D001679:Biogenic Amines; D010627:Phenethylamines; C029261:phenethylamine; D012701:Serotonin; D010649:Phenylalanine; D004298:Dopamine; D009638:Norepinephrine