Effect of hypercapnia and hypocapnia on tryptophan and tyrosine hydroxylation in rat brain.
The effects of induced hypo- and hypercapnia upon the rate of hydroxylation of tryptophan and tyrosine in the rat brain were studied by measuring the accumulation of 5-HTP and DOPA following administration of the aromatic L-aminoacid decarboxylase inhibitor 3-hydroxybenzylhydrazine HCl (NSD 1015). The results suggest that the hydroxylation of tryptophan varies directly with the tissue Po2. On the other hand, the hydroxylation of tyrosine did not show a simple relationship to Po2 but appeared to be influenced by pH changes.
D006916:5-Hydroxytryptophan / Q000378:metabolism; D000596:Amino Acids / Q000378:metabolism; D000641:Ammonia / Q000378:metabolism; D000818:Animals; D001921:Brain / Q000378:metabolism*; D050260:Carbohydrate Metabolism; D002245:Carbon Dioxide / Q000097:blood*; D004295:Dihydroxyphenylalanine / Q000378:metabolism; D006834:Hydrazines / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D006900:Hydroxylation; D006935:Hypercapnia / Q000378:metabolism*; D008297:Male; D010313:Partial Pressure; D010710:Phosphates / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D014364:Tryptophan / Q000378:metabolism*; D014443:Tyrosine / Q000378:metabolism*
D000596:Amino Acids; D006834:Hydrazines; D010710:Phosphates; D002245:Carbon Dioxide; D014443:Tyrosine; D004295:Dihydroxyphenylalanine; D000641:Ammonia; D014364:Tryptophan; D006916:5-Hydroxytryptophan