A new metabolic pathway of L-threo-3,4-dihydroxyphenylserine, a precursor amino acid of norepinephrine, in the brain. Studies by in vivo microdialysis.
{"title":"A new metabolic pathway of L-threo-3,4-dihydroxyphenylserine, a precursor amino acid of norepinephrine, in the brain. Studies by in vivo microdialysis.","authors":"W Maruyama, D Nakahara, M Naoi","doi":"10.1007/BF02252660","DOIUrl":null,"url":null,"abstract":"<p><p>The metabolism and the effects of L-threo-3,4-dihydroxyphenylserine (L-threo-DOPS) were studied in the rat brain striatum by in vivo microdialysis. In the brain L-threo-DOPS was metabolized by 3 different enzymes; aromatic L-amino acid decarboxylase, catechol-O-methyltransferase, and DOPS-aldolase. DOPS-aldolase was the main enzyme which metabolizes L-threo-DOPS. The amounts of the metabolites by L-amino acid decarboxylase (norepinephrine and its metabolites) were 0.4% of the total amounts of metabolites detected in the dialysate, while those by catechol-O-methyltransferase, 2.1%, and by DOPS-aldolase, 97.5%, after 100 min perfusion of L-threo-DOPS. L-threo-DOPS was found to increase extracellular levels of dopamine and serotonin, and to inhibit monoamine catabolism in the brain. Inhibition of DOPS-aldolase should improve its effectiveness as the supplement therapy of norepinephrine.</p>","PeriodicalId":16466,"journal":{"name":"Journal of Neural Transmission - Parkinson's Disease and Dementia Section","volume":"7 1","pages":"21-33"},"PeriodicalIF":0.0000,"publicationDate":"1994-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/BF02252660","citationCount":"11","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Neural Transmission - Parkinson's Disease and Dementia Section","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1007/BF02252660","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 11
Abstract
The metabolism and the effects of L-threo-3,4-dihydroxyphenylserine (L-threo-DOPS) were studied in the rat brain striatum by in vivo microdialysis. In the brain L-threo-DOPS was metabolized by 3 different enzymes; aromatic L-amino acid decarboxylase, catechol-O-methyltransferase, and DOPS-aldolase. DOPS-aldolase was the main enzyme which metabolizes L-threo-DOPS. The amounts of the metabolites by L-amino acid decarboxylase (norepinephrine and its metabolites) were 0.4% of the total amounts of metabolites detected in the dialysate, while those by catechol-O-methyltransferase, 2.1%, and by DOPS-aldolase, 97.5%, after 100 min perfusion of L-threo-DOPS. L-threo-DOPS was found to increase extracellular levels of dopamine and serotonin, and to inhibit monoamine catabolism in the brain. Inhibition of DOPS-aldolase should improve its effectiveness as the supplement therapy of norepinephrine.