title: Cytochrome P450-dependent drug oxidation activity of liver microsomes from Microminipigs, a possible new animal model for humans in non-clinical studies.
abstract: Small minipigs (Bland name, Micromini Pig; registered as a novel variety of pig in the Japanese Ministry of Agriculture, Forestry and Fisheries) were developed with the aim of non-clinical pharmacological/toxicological use. They were principally mated with<10 kg body weight at 7 months-old resulting in good handling. Cytochrome P450 (P450)-and flavin-containing monooxygenases (FMO)-dependent drug oxidation activity of liver microsomes prepared from male Microminipigs (8 months-old) was compared with that for pooled dogs, monkeys, and humans. High P450 2D-dependent bufuralol 1'-hydroxylation and FMO-dependent benzydamine N-oxygenation activity was observed in liver microsomes from Microminipigs. Typical P450 1A, 2B, 2C, 2E, and 3A-dependent drug oxidation activity was also seen in Microminipigs. However, occasional differences might give undetected low P450 2A-dependent coumarin 7-hydroxylation in Microminipigs at 8-months-old, in contrast to liver microsomes from one 10-days-old Microminipis and commercially available pooled minipigs which had low but detectable coumarin 7-hydroxylation activity. The present results suggest that there is some overlap in Microminipig and human P450 substrate specificity. These findings should provide important information for greater understanding of drug metabolism in Microminipigs, as an experimental animal model for non-clinical use.
authors.affiliation: Laboratory of Drug Metabolism and Pharmacokinetics, Showa Pharmaceutical University, Machida, Tokyo, Japan.
authors.forename: Norie
authors.initials: N
authors.lastname: Murayama
authors.forename: Naoki
authors.initials: N
authors.lastname: Kaneko
authors.forename: Kana
authors.initials: K
authors.lastname: Horiuchi
authors.forename: Katsuhiro
authors.initials: K
authors.lastname: Ohyama
authors.forename: Makiko
authors.initials: M
authors.lastname: Shimizu
authors.forename: Katzuhiko
authors.initials: K
authors.lastname: Ito
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Yamazaki
mesh_terms: D000818:Animals; D001189:Aryl Hydrocarbon Hydroxylases / Q000378:metabolism; D065702:Cytochrome P-450 CYP2B6; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism*; D004285:Dogs; D004353:Drug Evaluation, Preclinical; D006801:Humans; D008297:Male; D008862:Microsomes, Liver / Q000201:enzymology* / Q000378:metabolism; D023421:Models, Animal; D010084:Oxidation-Reduction; D010089:Oxidoreductases, N-Demethylating / Q000378:metabolism; D010105:Oxygenases / Q000378:metabolism*; D013552:Swine; D013556:Swine, Miniature
chemical_list: D003577:Cytochrome P-450 Enzyme System; D010105:Oxygenases; C020066:dimethylaniline monooxygenase (N-oxide forming); D001189:Aryl Hydrocarbon Hydroxylases; C585599:CYP2B6 protein, human; D065702:Cytochrome P-450 CYP2B6; D010089:Oxidoreductases, N-Demethylating