title: Effects of L-tryptophan on indoleamines and catecholamines in discrete brain regions of wild type and Lurcher mutant mice.
abstract: The biochemical parameters of the serotoninergic system were examined in wild type mice and Lurcher mutants after chronic treatment (40 days) with the serotonin (5-HT) precursor L-tryptophan (50 mg/kg; i.p.). Tissue contents in 5-HT, dopamine and noradrenaline, as well as some of their metabolites, were measured in frontal cortex, neostriatum, thalamus, brainstem, cerebellum and spinal cord by high-performance liquid chromatography. The tissue levels were used as a biochemical index of the function of the monoamine innervations in this animal model of cerebellar ataxia. The results show that Lurcher mutants retain higher concentrations of L-tryptophan and total indoleamines, but that 5-HT is probably stored in a non-releasable compartment. In the particular case of the hypoplastic cerebellum, the reorganization of 5-HT nerve terminals leads to an accrued indoleamine synthesis, indicating that the Lurcher mutants can accumulate 5-HT, but do not utilize it efficiently in synaptic transmission.
authors.affiliation: Centre de Recherche en Sciences Neurologiques, Département de physiologie, Faculté de médecine, Université de Montréal, Québec, Canada. readert@ere.umontreal.ca
authors.forename: T A
authors.initials: TA
authors.lastname: Reader
authors.forename: N
authors.initials: N
authors.lastname: Le Marec
authors.forename: A R
authors.initials: AR
authors.lastname: Ase
authors.forename: R
authors.initials: R
authors.lastname: Lalonde
mesh_terms: D000818:Animals; D001921:Brain / Q000378:metabolism*; D002395:Catecholamines / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid; D005260:Female; D006897:Hydroxyindoleacetic Acid / Q000378:metabolism*; D051379:Mice; D008817:Mice, Mutant Strains; D012701:Serotonin / Q000378:metabolism; D014364:Tryptophan / Q000494:pharmacology*
chemical_list: D002395:Catecholamines; D012701:Serotonin; D006897:Hydroxyindoleacetic Acid; D014364:Tryptophan