Differential effect of carbidopa on the concentration of rat pineal and hypothalamic indoleamines.
Carbidopa, an aromatic acid decarboxylase inhibitor, has been shown to significantly decrease the pineal concentration of melatonin, N-acetyl serotonin (NAS), serotonin (5-HT), and 5-hydroxyindoleacetic acid (5-HIAA) but not the hypothalamic concentrations of these indoles. Increased levels of 5-hydroxytryptophan (5-HTP) indicate that carbidopa directly inhibits 5-HTP decarboxylation, thus limiting 5-HT production. Possible practical implications of selective inhibition of pineal indoleamines by carbidopa are discussed.
D006916:5-Hydroxytryptophan / Q000378:metabolism*; D000818:Animals; D002230:Carbidopa / Q000494:pharmacology*; D006897:Hydroxyindoleacetic Acid / Q000378:metabolism*; D007031:Hypothalamus / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D008550:Melatonin / Q000378:metabolism*; D009928:Organ Specificity; D010870:Pineal Gland / Q000187:drug effects / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D012701:Serotonin / Q000031:analogs & derivatives / Q000378:metabolism*
D012701:Serotonin; D006897:Hydroxyindoleacetic Acid; D006916:5-Hydroxytryptophan; D008550:Melatonin; D002230:Carbidopa; C006389:N-acetylserotonin