Cytosolic epoxide hydrolase in fetal and adult human liver.
The epoxide hydrolase and glutathione S-transferase activity towards styrene oxide as substrate were investigated and compared in fetal and adult human liver cytosols. The rate of formation of styrene glycol from styrene oxide (nmole/min/mg protein) was 0.23 +/- 0.02 (means +/- SE; n = 10) in fetal and 0.83 +/- 0.05 (means +/- SE; n = 14) in adult liver specimens. The enzyme followed Michealis-Menten kinetics in the fetal liver. In adult liver specimens the enzyme showed biphasic kinetics. For comparative purposes, the cytosolic glutathione S-transferase activity was investigated in the cytosolic fractions from the same liver specimens. The fetal activity was 40% of the adult activity 3.9 +/- 0.50 (means +/- SE; n = 10) versus 9.94 +/- 1.75 (means +/- SE; n = 14) nmoles/min/mg protein.
D000328:Adult; D000368:Aged; D003600:Cytosol / Q000201:enzymology*; D004851:Epoxide Hydrolases / Q000032:analysis*; D005260:Female; D005333:Fetus / Q000201:enzymology*; D005982:Glutathione Transferase / Q000032:analysis*; D006801:Humans; D008099:Liver / Q000196:embryology / Q000201:enzymology*; D008297:Male; D008862:Microsomes, Liver / Q000201:enzymology; D008875:Middle Aged; D011247:Pregnancy; D013997:Time Factors
D005982:Glutathione Transferase; D004851:Epoxide Hydrolases; C022686:styrene oxide hydratase