title: Immunochemical detection of cytochrome P450 enzymes in liver microsomes of 27 cynomolgus monkeys.
abstract: The cynomolgus monkey is widely used as a primate model in preclinical studies because of its evolutionary closeness to humans. Despite their importance in drug metabolism, the content of each cytochrome P450 (P450) enzyme has not been systematically determined in cynomolgus monkey livers. In this study, liver microsomes of 27 cynomolgus monkeys were analyzed by immunoblotting using selective P450 antibodies. The specificity of each antibody was confirmed by analyzing the cross-reactivity against 19 CYP1-3 subfamily enzymes using recombinant proteins. CYP2A, CYP2B6, CYP2C9/19, CYP2C76, CYP2D, CYP2E, CYP3A4, and CYP3A5 were detected in all 27 animals. In contrast, CYP1A, CYP1D, and CYP2J were below detectable levels in all liver samples. The average content of each P450 showed that among the P450s analyzed CYP3A (3A4 and 3A5) was the most abundant (40% of total immunoquantified P450), followed by CYP2A (25%), CYP2C (14%), CYP2B6 (13%), CYP2E1 (11%), and CYP2D (3%). No apparent sex differences were found for any P450. Interanimal variations ranged from 2.6-fold (CYP3A) to 11-fold (CYP2C9/19), and most P450s (CYP2A, CYP2D, CYP2E, CYP3A4, and CYP3A5) varied 3- to 4-fold. To examine the correlations of P450 content with enzyme activities, metabolic assays were performed in 27 cynomolgus monkey livers using 7-ethoxyresorufin, coumarin, pentoxyresorufin, flurbiprofen, bufuralol, dextromethorphan, and midazolam. CYP2D and CYP3A4 contents were significantly correlated with typical reactions of human CYP2D (bufuralol 1'-hydroxylation and dextromethorphan O-deethylation) and CYP3A (midazolam 1'-hydroxylation and 4-hydroxylation). The results presented in this study provide useful information for drug metabolism studies using cynomolgus monkeys.
authors.affiliation: Pharmacokinetics and Bioanalysis Center, Shin Nippon Biomedical Laboratories, Ltd., 16-1 Minami Akasaka, Kainan, Wakayama, 642-0017, Japan.
authors.forename: Shotaro
authors.initials: S
authors.lastname: Uehara
authors.forename: Norie
authors.initials: N
authors.lastname: Murayama
authors.forename: Yasuharu
authors.initials: Y
authors.lastname: Nakanishi
authors.forename: Darryl C
authors.initials: DC
authors.lastname: Zeldin
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Yamazaki
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Uno
mesh_terms: D000818:Animals; D000925:Anticoagulants / Q000378:metabolism; D001189:Aryl Hydrocarbon Hydroxylases / Q000276:immunology / Q000378:metabolism; D003374:Coumarins / Q000378:metabolism; D051544:Cytochrome P-450 CYP3A / Q000276:immunology / Q000378:metabolism; D003577:Cytochrome P-450 Enzyme System / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D057075:Enzyme Assays; D005260:Female; D006801:Humans; D006900:Hydroxylation; D015151:Immunoblotting; D008658:Inactivation, Metabolic; D008252:Macaca fascicularis; D008297:Male; D008862:Microsomes, Liver / Q000201:enzymology* / Q000378:metabolism; D010078:Oxazines / Q000378:metabolism; D012680:Sensitivity and Specificity; D013250:Steroid Hydroxylases / Q000276:immunology / Q000378:metabolism
chemical_list: D000925:Anticoagulants; D003374:Coumarins; D010078:Oxazines; C007649:ethoxyresorufin; D003577:Cytochrome P-450 Enzyme System; C030123:coumarin; D013250:Steroid Hydroxylases; D001189:Aryl Hydrocarbon Hydroxylases; C510164:CYP3A5 protein, human; D051544:Cytochrome P-450 CYP3A; C029009:steroid hormone 7-alpha-hydroxylase; C510163:CYP3A4 protein, human