title: Cytochrome P450 1A-dependent activities in deer, cattle and horses.
abstract: The objective of this study was to investigate and characterize the metabolic activities of CYP1A in deer, cattle and horses in comparison to those of rats using ethoxyresorufin O-deethylation (EROD) and methoxyresorufin O-demethylation (MROD) assays. We performed an inhibition study for these activities using anti-rat CYP1A1 antibody and identified that these activities were due to the CYP1A subfamily. Interspecies differences in the CYP1A-dependent activities were highly observed in this study. In particular, we found that the horse had the highest EROD and MROD activities among the examined animal species. In the kinetic analysis, the horses showed the highest Vmax and catalytic efficiency (Vmax/Km), followed by the cattle, deer and rats.
authors.affiliation: Laboratory of Toxicology, Department of Environmental Veterinary Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Kita-ku, Sapporo, Japan. ishizum@vetmed.hokudai.ac.jp
authors.forename: Wageh Sobhy
authors.initials: WS
authors.lastname: Darwish
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Ikenaka
authors.forename: Elsaid Abozeid
authors.initials: EA
authors.lastname: Eldaly
authors.forename: Marumi
authors.initials: M
authors.lastname: Ohno
authors.forename: Kentaro Q
authors.initials: KQ
authors.lastname: Sakamoto
authors.forename: Shoichi
authors.initials: S
authors.lastname: Fujita
authors.forename: Mayumi
authors.initials: M
authors.lastname: Ishizuka
mesh_terms: D000818:Animals; D002417:Cattle; D019363:Cytochrome P-450 CYP1A1 / Q000037:antagonists & inhibitors / Q000378:metabolism; D019388:Cytochrome P-450 CYP1A2 / Q000378:metabolism*; D065607:Cytochrome P-450 Enzyme Inhibitors; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism*; D003670:Deer; D006736:Horses; D007700:Kinetics; D008862:Microsomes, Liver / Q000201:enzymology*; D051381:Rats; D013045:Species Specificity
chemical_list: D065607:Cytochrome P-450 Enzyme Inhibitors; D003577:Cytochrome P-450 Enzyme System; C076307:methoxyresorufin-O-demethylase; D019363:Cytochrome P-450 CYP1A1; D019388:Cytochrome P-450 CYP1A2