Rapid reversal by naloxone of the chronic effects of morphine on rat liver and brain tryptophan metabolism.
The chronic morphine-induced inhibition of rat liver tryptophan pyrrolase activity and the resultant increases in tryptophan availability to the brain and brain 5-hydroxytryptamine (5-HT) synthesis are reversed within 10 min after naloxone administration. The possible involvement of hepatic tryptophan metabolism in morphine dependence is briefly discussed.
D000818:Animals; D001921:Brain / Q000378:metabolism*; D008099:Liver / Q000378:metabolism*; D008297:Male; D009020:Morphine / Q000037:antagonists & inhibitors*; D009270:Naloxone / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D012701:Serotonin / Q000096:biosynthesis; D014364:Tryptophan / Q000378:metabolism*
D012701:Serotonin; D009270:Naloxone; D009020:Morphine; D014364:Tryptophan