TY - JOUR
T1 - Kynurenine 3-Hydroxylase in Brain
T2 - Species Activity Differences and Effect of Gerbil Cerebral Ischemia
AU - Saito, Kuniaki
AU - Quearry, Bonnie J.
AU - Saito, Misato
AU - Nowak, Thaddeus S.
AU - Markey, Sanford P.
AU - Heyes, Melvyn P.
PY - 1993
Y1 - 1993
N2 - We have developed a rapid and highly sensitive assay for brain kynurenine 3-hydroxylase activity. The present study determined some characteristics and species differences of kynurenine 3-hydroxylase activity in brain and evaluated the response of this enzyme to cerebral ischemia. The kynurenine 3-hydroxylase assay is based on the conversion of L-kynurenine to 3-hydroxykynurenine in vitro and the quantification of 3-hydroxykynurenine by high-performance liquid chromatography. Kynurenine 3-hydroxylase activity was detected in human, macaque, rat, mouse, and gerbil brain. Regional gerbil brain activities ranged from 20 to 50 nmol/g/h, while kynurenine 3-hydroxylase activities in other species were one order of magnitude lower. Kynurenine 3-hydroxylase was also detected in lung, kidney, spleen, intestine, and liver of gerbils, with activities larger than in brain. Delayed increases in the activity of kynurenine 3-hydroxylase occur in several brain regions following transient ischemia in gerbils. These changes are particularly marked in regions that showed the most extensive brain damage (hippocampus and striatum). Kynurenine 3-hydroxylase may have an important role in determining the flux of kynurenine in brain.
AB - We have developed a rapid and highly sensitive assay for brain kynurenine 3-hydroxylase activity. The present study determined some characteristics and species differences of kynurenine 3-hydroxylase activity in brain and evaluated the response of this enzyme to cerebral ischemia. The kynurenine 3-hydroxylase assay is based on the conversion of L-kynurenine to 3-hydroxykynurenine in vitro and the quantification of 3-hydroxykynurenine by high-performance liquid chromatography. Kynurenine 3-hydroxylase activity was detected in human, macaque, rat, mouse, and gerbil brain. Regional gerbil brain activities ranged from 20 to 50 nmol/g/h, while kynurenine 3-hydroxylase activities in other species were one order of magnitude lower. Kynurenine 3-hydroxylase was also detected in lung, kidney, spleen, intestine, and liver of gerbils, with activities larger than in brain. Delayed increases in the activity of kynurenine 3-hydroxylase occur in several brain regions following transient ischemia in gerbils. These changes are particularly marked in regions that showed the most extensive brain damage (hippocampus and striatum). Kynurenine 3-hydroxylase may have an important role in determining the flux of kynurenine in brain.
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U2 - 10.1006/abbi.1993.1567
DO - 10.1006/abbi.1993.1567
M3 - Article
C2 - 8239646
AN - SCOPUS:0027488558
SN - 0003-9861
VL - 307
SP - 104
EP - 109
JO - Archives of Biochemistry and Biophysics
JF - Archives of Biochemistry and Biophysics
IS - 1
ER -