title: Decreased serum and red blood cell kynurenic acid levels in Alzheimer's disease.
abstract: Kynurenine aminotransferases (KAT I and KAT II) are responsible for the transamination of kynurenine (KYN) to form kynurenic acid (KYNA), an excitatory amino acid receptor antagonist. Since these members of the kynurenine pathway (KP) are proposed to be involved in the pathogenesis of Alzheimer's dementia (AD), the activities of these enzymes and the levels of these metabolites were measured in the plasma and red blood cells (RBCs) of AD and control subjects together with the inheritance of the apolipoprotein (APOE) epsilon4 allele. KYNA levels were significantly decreased both in the plasma and in the RBCs in AD, but the levels of KYN and the activities of KAT I and KAT II remained unchanged. No association has been found with the possession of the epsilon4 allele. These findings indicate an altered peripheral KP in AD regardless of the APOE status of the probands.
authors.affiliation: Department of Psychiatry, University of Szeged, Szeged, Hungary.
authors.forename: Zsuzsanna
authors.initials: Z
authors.lastname: Hartai
authors.forename: Anna
authors.initials: A
authors.lastname: Juhász
authors.forename: Agnes
authors.initials: A
authors.lastname: Rimanóczy
authors.forename: Tamás
authors.initials: T
authors.lastname: Janáky
authors.forename: Teodóra
authors.initials: T
authors.lastname: Donkó
authors.forename: László
authors.initials: L
authors.lastname: Dux
authors.forename: Botond
authors.initials: B
authors.lastname: Penke
authors.forename: Gábor K
authors.initials: GK
authors.lastname: Tóth
authors.forename: Zoltán
authors.initials: Z
authors.lastname: Janka
authors.forename: János
authors.initials: J
authors.lastname: Kálmán
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000483:Alleles; D000544:Alzheimer Disease / Q000097:blood*; D001057:Apolipoproteins E / Q000235:genetics; D004912:Erythrocytes / Q000378:metabolism*; D005260:Female; D005838:Genotype; D006801:Humans; D007736:Kynurenic Acid / Q000097:blood*; D007737:Kynurenine / Q000378:metabolism; D008297:Male; D000637:Transaminases / Q000378:metabolism
chemical_list: D001057:Apolipoproteins E; D007737:Kynurenine; D000637:Transaminases; C021481:kynurenine-oxoglutarate transaminase; D007736:Kynurenic Acid