A comparison of the effects of carbon monoxide intoxication and low-oxygen gas mixtures on cerebral biogenic amine metabolism.
The effects of 1% CO on cerebral biogenic amine metabolism was studied by measurement of cerebral hemisphere contents of 5-hydroxytryptophan (5-HTP), 5-hydroxytryptamine (5-HT), 5-hydroxyindoleacetic acid (5-HIAA), dihydroxyphenylalanine (DOPA) and dopamine (DA). The results indicated that 1% CO is associated with an increased cerebral hemisphere content of DA. In CO-exposed animals treated with the decarboxylase inhibitor, 3-hydroxybenzyl hydrazine, the rate of tryptophan hydroxylation was reduced. When the duration of exposure to a given range of arterial oxygen content was matched to that of a group exposed to a low-oxygen gas mixture (5% O2) the rates of tryptophan hydroxylation were equivalent. This suggests that at a given arterial total oxygen content the tissue oxygen tension and supply are equivalent in low O2 or CO hypoxia. Assessment of the effects of 1% CO on tyrosine hydroxylation indicated no significant effect on this enzyme step.
D006916:5-Hydroxytryptophan / Q000378:metabolism; D000818:Animals; D002249:Carbon Monoxide Poisoning / Q000378:metabolism*; D002540:Cerebral Cortex / Q000187:drug effects / Q000378:metabolism* / Q000503:physiopathology; D004295:Dihydroxyphenylalanine / Q000378:metabolism; D004298:Dopamine / Q000378:metabolism*; D006834:Hydrazines / Q000494:pharmacology; D006897:Hydroxyindoleacetic Acid / Q000378:metabolism; D002534:Hypoxia, Brain / Q000378:metabolism*; D008297:Male; D010293:Pargyline / Q000494:pharmacology; D011339:Probenecid / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D012701:Serotonin / Q000378:metabolism*
D006834:Hydrazines; D012701:Serotonin; D006897:Hydroxyindoleacetic Acid; D004295:Dihydroxyphenylalanine; D010293:Pargyline; C004297:3-hydroxybenzylhydrazine; D006916:5-Hydroxytryptophan; D011339:Probenecid; D004298:Dopamine