High-performance liquid chromatographic assay of human lymphocyte kynureninase activity levels.
Human lymphocyte kynureninase activity was assessed in homogenized cells by determination of 3-hydroxyanthranilic acid production as a function of time after addition of the substrate, 3-hydroxykynurenine. The product, 3-hydroxyanthranilic acid, was determined by isocratic high-performance liquid chromatography and fluorescence detection. Mean (+/- S.D.) lymphocyte kynureninase activity in a group (n = 12) of vitamin B6-deficient men was 5.04 +/- 0.81 pmol 3-hydroxyanthranilic acid formed per mg protein per min, which was significantly (p = 0.005) lower than the 6.69 +/- 1.70 pmol 3-hydroxyanthranilic acid formed per mg protein per min in men with a normal vitamin B6 status. This indicates that lymphocyte kynureninase activity is depressed during a vitamin B6 deficiency.
Department of Chemical Pathology, Faculty of Medicine, University of Pretoria, South Africa.
J B
JB
Ubbink
W J
WJ
Vermaak
S H
SH
Bissbort
D015095:3-Hydroxyanthranilic Acid / Q000737:chemistry; D002851:Chromatography, High Pressure Liquid; D006801:Humans; D006867:Hydrolases / Q000097:blood*; D007737:Kynurenine / Q000031:analogs & derivatives / Q000737:chemistry; D008214:Lymphocytes / Q000201:enzymology*; D008297:Male; D009752:Nutritional Status; D011736:Pyridoxine / Q000097:blood; D013379:Substrate Specificity; D026681:Vitamin B 6 Deficiency / Q000201:enzymology
D015095:3-Hydroxyanthranilic Acid; C005045:3-hydroxykynurenine; D007737:Kynurenine; D006867:Hydrolases; C021480:kynureninase; D011736:Pyridoxine