Tryptophan and 5-hydroxyindoles in different CNS regions following acute morphine.
Morphine induces naloxone-reversible increases of tryptophan and 5-hydroxyindoles in rat cerebral hemispheres, thalamus and cerebellum, but does not do so in striatum, hypothalamus, hippocampus and brain stem. Morphine also induces a rise in spinal cord 5-HIAA which is antagonized by naloxone, but there is no parallel change in tryptophan. Increases in brain 5-hydroxyindoles may be related to greater availability of tryptophan, but the elevation in spinal cord 5-HIAA appears to be unrelated to precursor availability.
D000818:Animals; D001923:Brain Chemistry / Q000187:drug effects*; D006897:Hydroxyindoleacetic Acid / Q000032:analysis*; D008297:Male; D009020:Morphine / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D009270:Naloxone / Q000494:pharmacology; D051381:Rats; D012701:Serotonin / Q000032:analysis*; D014364:Tryptophan / Q000032:analysis*
D012701:Serotonin; D009270:Naloxone; D006897:Hydroxyindoleacetic Acid; D009020:Morphine; D014364:Tryptophan