Interindividual variability of carbonyl reductase levels in human livers.
Interindividual variability of carbonyl reductase levels in human livers (N = 11) was examined by measuring reductase activity toward various substrates and by western blot analysis using anti-rat ovarian carbonyl reductase CR2 antibody. The carbonyl reductase activity toward p-nitrobenzaldehyde (PNBA) (58.1 +/- 5.4 nmol/mg protein/min, mean +/- SE) was highest among the substrates examined, followed by 4-benzoylpyridine (4BP) (14.4 +/- 2.0 nmol/mg protein/min) and p-nitroacetophenone (PNAP) (2.00 +/- 0.37 nmol/mg protein/min). The reductase activity (6.33 +/- 0.56 pmol/mg protein/min) toward 13,14-dihydro-15-keto-prostaglandin F2 alpha (15KD-PGF2 alpha), which is a diagnostic substrate for rat ovarian carbonyl reductases, was relatively high compared to that in other species. Western blot analysis revealed that each human liver contained several immunoreactive proteins to anti-CR2 antibody. The activities toward 15KD-PGF2 alpha (r = 0.85, P < 0.01) and 4BP (r = 0.84, P < 0.01), but not PNBA (r = 0.53, not significant) or PNAP (r = 0.52, not significant), were closely correlated with the relative amounts of the high molecular weight immunoreactive proteins determined with a densitometer. Thus, the major carbonyl reductases in human liver are similar to those of rat ovarian enzymes.
Iwata
N
N
Department of Forensic Medicine, Tokyo Medical College, Shinjuku, Japan.
Inazu
N
N
Hara
S
S
Yanase
T
T
Kano
S
S
Endo
T
T
Kuriiwa
F
F
Sato
Y
Y
Satoh
T
T
D000098:Acetophenones / Q000378:metabolism; D000328:Adult; D000429:Alcohol Oxidoreductases / Q000737:chemistry / Q000378:metabolism*; D001547:Benzaldehydes / Q000378:metabolism; D015237:Dinoprost / Q000378:metabolism; D005260:Female; D006801:Humans; D008099:Liver / Q000201:enzymology*; D008297:Male; D008875:Middle Aged; D008970:Molecular Weight; D011725:Pyridines / Q000378:metabolism; D013379:Substrate Specificity
D000098:Acetophenones; D001547:Benzaldehydes; D011725:Pyridines; C001972:4-nitroacetophenone; C066738:4-benzoylpyridine; C029915:4-nitrobenzaldehyde; D015237:Dinoprost; D000429:Alcohol Oxidoreductases