Brain tryptophan hydroxylation: dependence on arterial oxygen tension

Science. 1973 Oct 5;182(4107):72-4. doi: 10.1126/science.182.4107.72.

Abstract

The accumulation of cerebral 5-hydroxytryptophan after decarboxylase inhibition was decreased in rats maintained at arterial O(2) tensions below 60 mm-Hg. In contrast, brain lactate was stable above 40 mm-Hg and brain adenosine triphosphate, adenosine diphosphate, and adenosine monophosphate were unchanged above 30 mm-Hg. There was a linear correlation of brain 5-hydroxytryptophan accumulation to cerebral venous O(2) tension. Cerebral tryptophan hydroxylase appears to have a poor affinity for oxygen and to be affected by slight hypoxia. The resultant decreases in monoamine neurotransmitter metabolism may explain the behavioral changes of mild oxygen deprivation.

MeSH terms

  • 5-Hydroxytryptophan / analysis
  • Adenosine Diphosphate / metabolism
  • Adenosine Monophosphate / metabolism
  • Adenosine Triphosphate / metabolism
  • Animals
  • Benzyl Compounds / pharmacology
  • Brain / enzymology*
  • Brain / metabolism
  • Brain Chemistry / drug effects
  • Carbon Dioxide / blood
  • Femoral Artery
  • Hydrazines / pharmacology
  • Hydrogen-Ion Concentration
  • Hypoxia / enzymology
  • Hypoxia / metabolism
  • Lactates / metabolism
  • Male
  • Mixed Function Oxygenases / metabolism*
  • Oxygen / blood*
  • Phosphocreatine / metabolism
  • Pyruvates / metabolism
  • Rats
  • Tryptophan Hydroxylase / antagonists & inhibitors
  • Tryptophan Hydroxylase / metabolism

Substances

  • Benzyl Compounds
  • Hydrazines
  • Lactates
  • Pyruvates
  • Phosphocreatine
  • Carbon Dioxide
  • Adenosine Monophosphate
  • Adenosine Diphosphate
  • Adenosine Triphosphate
  • 5-Hydroxytryptophan
  • Mixed Function Oxygenases
  • Tryptophan Hydroxylase
  • Oxygen