Catalogo Articoli (Spogli Riviste)

OPAC HELP

Titolo:
Effect of a tyrosine-free amino acid mixture on regional brain catecholamine synthesis and release
Autore:
McTavish, SFB; Cowen, PJ; Sharp, T;
Indirizzi:
Univ Oxford, Radcliffe Infirm, Dept Clin Pharmacol, Oxford OX2 6HE, England Univ Oxford Oxford England OX2 6HE in Pharmacol, Oxford OX2 6HE, England Univ Oxford, Warneford Hosp, Dept Psychiat, Oxford, England Univ Oxford Oxford England rneford Hosp, Dept Psychiat, Oxford, England
Titolo Testata:
PSYCHOPHARMACOLOGY
fascicolo: 2, volume: 141, anno: 1999,
pagine: 182 - 188
Fonte:
ISI
Lingua:
ENG
Soggetto:
ANTIDEPRESSANT ACTION; TRYPTOPHAN DEPLETION; RAT STRIATUM; DOPAMINE; AMPHETAMINE; MICRODIALYSIS; PHENYLALANINE; METABOLISM; BARRIER;
Keywords:
tyrosine depletion; catecholamine; dopamine; noradrenaline; microdialysis;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Life Sciences
Citazioni:
24
Recensione:
Indirizzi per estratti:
Indirizzo: Sharp, T Univ Oxford, Radcliffe Infirm, Dept Clin Pharmacol, Oxford OX2 6HE, England Univ Oxford Oxford England OX2 6HE col, Oxford OX2 6HE, England
Citazione:
S.F.B. McTavish et al., "Effect of a tyrosine-free amino acid mixture on regional brain catecholamine synthesis and release", PSYCHOPHAR, 141(2), 1999, pp. 182-188

Abstract

We report the effects of a tyrosine (and phenylalanine)-free amino acid mixture on tyrosine levels, ex vivo catecholamine synthesis and in vivo catecholamine release in brain regions of the rat. Administration of a tyrosine-free amino acid load reduced tissue levels of tyrosine (-50% after 2 h) in all brain regions examined (frontal cortex, hippocampus. striatum). The tyrosine-free amino acid mixture also reduced DOPA accumulation: this effect was most marked in striatum (-44%) and nucleus accumbens (-34%). areas with a predominantly dopaminergic innervation. Smaller decreases (-20-24%) were detected in other areas (cortex, hippocampus and hypothalamus). The effect on DOPA accumulation was prevented by supplementing the mixture with tyrosine/phenylalanine. The tyrosine-free amino acid mixture did not alter 5-HTP accumulation in any region. In microdialysis experiments, the tyrosine-freeamino acid mixture did not consistently alter striatal extracellular dopamine under basal conditions but markedly, and dose-dependently. reduced the release of dopamine induced by amphetamine. In contrast. the tyrosine-free amino acid mixture did not alter either basal or amphetamine-evoked releaseof noradrenaline in hippocampus. Overall, these studies indicate that administration of a tyrosine-free amino acid mixture to rats depletes brain tyrosine to cause a decrease in regional brain catecholamine synthesis and release. Dopaminergic neurones appear to be more vulnerable to tyrosine depletion than noradrenergic neurones.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 01/06/20 alle ore 00:33:34