Pet ct spect small animal scanner 62

The investigators were blinded to allocation during experiments and outcome assessment for all metabolic phenotyping. For glucose tolerance tests (GTT), mice were fasted for 6 hours. Glucose levels in tail blood were measured with a standard glucometer at the indicated times after an intraperitoneal (IP) injection of D-glucose (1g/kg BW for lean mice and AAV virus injected obese mice; 0.75g/kg BW for HFD mice). For insulin tolerance test (ITT), mice were fasted for 4 hours and blood glucose levels were measured at the above indicated times after an IP injection of insulin (HumulinR, 1U/kg BW for lean mice and AAV virus injected obese mice; 1.25U/kg BW for HFD mice). Mouse body composition (fat and lean mass, and water content) was measured by Nuclear Magnetic Resonance (NMR)^{18 (link)}. Visceral and subcutaneous fat were imaged by Siemen’s Inveon PET/CT/SPECT small animal scanner ^{62 (link)}. CT parameters were 220° degree of rotation, 360 steps, 500 ms exposure time, 50 kV/500microamps, binning of 4. Analysis performed on Inveon Research Workplace 4.2.0.15. Metabolic measurements of energy expenditure, respiratory exchange ratio, oxygen consumption, carbon dioxide production, food intake, and physical activity were performed using CLAMS (Comprehensive Lab Animal Monitoring System, Columbus Instruments) by University of Iowa Metabolic Phenotyping Core.