Decreased protein synthesis in hypothalamic nuclei following L-5-hydroxytryptophan in intact and p-chlorophenylalanine-pretreated rats.
The rate of protein synthesis was estimated in individual hypothalamic nuclei by a quantitative autoradiographic technique with L-[35S]methionine. The i.v. administration of 60 mg/kg L-5-hydroxytryptophan (40 min before) resulted in a 45-55% decrease of overall protein synthesis rate in all the hypothalamic nuclei examined. In rats pretreated (42 h before) with a single i.v. injection of 280 mg/kg p-chlorophenylalanine, a drug which is known to deplete brain serotonin concentration, the administration of 60 mg/kg L-5-hydroxytryptophan resulted in a 50-75% decrease of protein synthesis rates in the hypothalamic nuclei. These results suggest that the systemic administration of large doses of L-5-hydroxytryptophan may inhibit protein synthesis in hypothalamic nuclei directly or indirectly after the conversion of this compound to serotonin.
Lepetit
P
P
Groupe de Neurochimie Fonctionnelle, INSERM U171, CNRS UA1195, Hôpital Lyon-Sud, Pierre Bénite, France.
Touret
M
M
Grange
E
E
Gay
N
N
Bobillier
P
P
D006916:5-Hydroxytryptophan / Q000494:pharmacology*; D000818:Animals; D010134:Fenclonine / Q000494:pharmacology*; D007031:Hypothalamus / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D008715:Methionine / Q000378:metabolism; D009928:Organ Specificity; D014176:Protein Biosynthesis; D051381:Rats; D011919:Rats, Inbred Strains; D012016:Reference Values
D008715:Methionine; D006916:5-Hydroxytryptophan; D010134:Fenclonine