Tuyển tập các báo cáo nghiên cứu khoa học quốc tế về bệnh thú y đề tài: Phenotype of peroxisome proliferator-activated receptor-α(PPARα)deficient mice on mixed background fed high fat diet | J. Vet. Sci. 2003 4 3 239-244 JOURNAL OF Veterinary Science Phenotype of peroxisome proliferator-activated receptor-a PPARa deficient mice on mixed background fed high fat diet Bang Hyun Kim Young Suk Won1 Eun-Young Kim2 Mijung Yoon2 Ki-Taek Nam Goo Taeg Oh1 and Dae-Yong Kim3 Department of Toxicology National Institute of Toxicological Research Korea Food and Drug Administration Seoul 122-704 Korea 1 Genetic Resources Center Korea Research Institute of Bioscience and Biotechnology Daejeon 305-600 Korea 2Department of Life Science Mokwon University Daejeon 302-729 Korea 3Department of Pathology College of Veterinary Medicine and School of Agricultural Biotechnology Seoul National University Seoul 151-742 Korea Considerable controversy exists in determining the role of peroxisome proliferator-activated receptor-a PPARa on obesity. Previous reports demonstrated that PPARa is a critical modulator of lipid homeostasis but the overt obese phenotypic characterization in the strain of PPAR deficient PPARa- - mice is influenced by other factors including diet and genetics. Therefore it is necessary to establish the phenotypic characterization of PPARa- -mice prior to the obesity-related study. In this study we observed phenotype of PPARa- - mice on mixed genetic background C57BL 6Nx129 Sv fed a high fat diet for 16 weeks. PPARa- - mice regardless of sex raised body growth rate significantly comparing with wild type and showed male-specific fatty change in the liver. They were shown to lack hepatic induction of PPARa target genes encoding enzymes for fatty acid P-oxidation. Key words Phenotype PPARa- - mice C57BL 6Nx129 Sv high fat diet Introduction Peroxisome proliferator-activated receptors PPARs are members of the nuclear hormone receptor superfamily which form heterodimers with the retinoid X receptor 4 8 . They play an important role in the regulation of genes involved in lipid utilization and storage lipoprotein metabolism adipocyte differentiation and insulin action.