High oxidative stress in mouse adipose tissue. Levels of F2-isoprostanes (top) and methionine sulfoxides (bottom) in young male C57BL/6 mice. Bars represent mean levels of indicated oxidation moiety (± SEM) from four animals for each indicated measurement. Samples shown represent epididymal depot/visceral fat (adipose tissue), quadriceps (skeletal muscle), and liver. Dashed line indicates mean value for adipose tissue in low-fat (normal)-fed animals. High-fat diet animals were fed a defined diet with 45% kCal from fat (Research Diets D12451P) for 16 weeks. Isoprostanes were measured as previously described . Methionine sulfoxides were measured by immunoblot using methionine sulfoxide from Oxford Biochemical.