title: In vivo imaging of lipid storage and regression in diet-induced obesity during nutrition manipulation.
abstract: Changes in adipose tissue distribution and ectopic fat storage in, liver and skeletal muscle tissue impact whole body insulin sensitivity in both humans and experimental animals. Numerous mouse models of obesity, insulin resistance, and diabetes exist; however, current methods to assess mouse phenotypes commonly involve direct harvesting of the tissues of interest, precluding the possibility of repeated measurements in the same animal. In this study, we demonstrate that whole body 3-D imaging of body fat composition can be used to analyze distribution as well as redistribution of fat after intervention by repeated assessment of intrahepatocellular lipids (IHCL), intra-abdominal, subcutaneous, and total adipose tissue (IAT, SAT, and TAT) and brown adipose tissue (BAT). C57BL/6J mice fed a cafeteria diet for 16 wk were compared with mice fed standard chow for 16 wk and mice switched from café diet to standard chow after 12 wk. MRI determinations were made at 9 and 15 wk, and autopsy was performed at 16 wk. There was a strong correlation between MRI-calculated weights in vivo at 15 wk and measured weights at 16 wk ex vivo for IAT (r = 0.99), BAT (r = 0.93), and IHCL (r = 0.97). IHCL and plasma insulin increased steeply relative to body weight at body weights above 45 g. This study demonstrates that the use of 3-D imaging to assess body fat composition may allow substantial reductions in animal usage. The dietary interventions indicated that a marked metabolic deterioration occurred when the mice had gained a certain fat mass.
authors.affiliation: AstraZeneca R&D, PHB Imaging, Pepparedsleden 1, SE-43183 Mölndal, Sweden. abdel.bidar@astrazeneca.com
authors.forename: Abdel Wahad
authors.initials: AW
authors.lastname: Bidar
authors.forename: Karolina
authors.initials: K
authors.lastname: Ploj
authors.forename: Christopher
authors.initials: C
authors.lastname: Lelliott
authors.forename: Karin
authors.initials: K
authors.lastname: Nelander
authors.forename: Maria Sörhede
authors.initials: MS
authors.lastname: Winzell
authors.forename: Gerhard
authors.initials: G
authors.lastname: Böttcher
authors.forename: Jan
authors.initials: J
authors.lastname: Oscarsson
authors.forename: Leonard
authors.initials: L
authors.lastname: Storlien
authors.forename: Paul D
authors.initials: PD
authors.lastname: Hockings
mesh_terms: D000273:Adipose Tissue / Q000000981:diagnostic imaging* / Q000378:metabolism; D000821:Animal Feed; D000818:Animals; D001823:Body Composition; D050218:Body Fat Distribution / Q000295:instrumentation*; D003430:Cross-Sectional Studies; D004195:Disease Models, Animal; D004734:Energy Metabolism / Q000502:physiology; D005260:Female; D021621:Imaging, Three-Dimensional / Q000662:veterinary; D007333:Insulin Resistance / Q000502:physiology; D008099:Liver / Q000000981:diagnostic imaging* / Q000378:metabolism; D008137:Longitudinal Studies; D008279:Magnetic Resonance Imaging / Q000662:veterinary; D009682:Magnetic Resonance Spectroscopy; D051379:Mice; D008810:Mice, Inbred C57BL; D009765:Obesity / Q000097:blood / Q000000981:diagnostic imaging* / Q000378:metabolism; D010641:Phenotype; D011859:Radiography; D011897:Random Allocation; D014280:Triglycerides / Q000097:blood
chemical_list: D014280:Triglycerides