title: Content of kynurenic acid and activity of kynurenine aminotransferases in mammalian eyes.
abstract: The present study investigated the kynurenic acid (KYNA) contents and kynurenine aminotransferase (KAT I and II) activity in structures of the human, monkey, rabbit and bovine eye. KYNA levels were investigated with HPLC and detected fluorimetrically. The activity of KAT I and II was assayed as quantitative analysis of newly synthesized KYNA in vitro. Mean KYNA levels (+/-SD) in the human retina and vitreous body were 36.8 +/- 7.6 and 33.1 +/- 6.2 pmol/g wet tissue weight, respectively. In human eyes, KAT I activity in the vitreous body was 0.57 +/- 0.28, that of KAT II was 2.56 +/- 0.69. KAT I activity in the retina was 3.42 +/- 1.17 and that of KAT II 10.75 +/- 9.2. (KAT activity is expressed as KYNA synthesis in picomoles per gram wet tissue weight per hour.) The values of KYNA and KAT observed in other mammalian species tested were in the same range. In conclusion, KYNA and KAT enzymatic activity are present in the structures of human and other mammalian eyes.
authors.affiliation: Tadeusz Krwawicz Chair of Ophthalmology and 1st Eye Hospital, Lublin, Poland. zaro@panaceum.am.lublin.pl
authors.forename: Tomasz
authors.initials: T
authors.lastname: Zarnowski
authors.forename: Robert
authors.initials: R
authors.lastname: Rejdak
authors.forename: Zbigniew
authors.initials: Z
authors.lastname: Zagorski
authors.forename: Anselm G M
authors.initials: AG
authors.lastname: Juenemann
authors.forename: Eberhart
authors.initials: E
authors.lastname: Zrenner
authors.forename: Tomasz
authors.initials: T
authors.lastname: Kocki
authors.forename: Ewa M
authors.initials: EM
authors.lastname: Urbanska
authors.forename: Waldemar A
authors.initials: WA
authors.lastname: Turski
mesh_terms: D000818:Animals; D001082:Aqueous Humor / Q000737:chemistry; D002417:Cattle; D005123:Eye / Q000737:chemistry*; D006801:Humans; D007498:Iris / Q000737:chemistry; D007736:Kynurenic Acid / Q000032:analysis*; D008253:Macaca mulatta; D011817:Rabbits; D012160:Retina / Q000737:chemistry; D000637:Transaminases / Q000032:analysis*; D014822:Vitreous Body / Q000737:chemistry
chemical_list: D000637:Transaminases; C021481:kynurenine-oxoglutarate transaminase; D007736:Kynurenic Acid