Echo mri 100 whole body composition analyzer

Body composition and body temperature data were obtained as we previously described [16 (link)]. Whole-body composition was monitored using Echo MRI-100 whole-body composition analyzer (Echo Medical Systems, Houston, TX). For the cold exposure study, mice were individually caged in 4°C cold room for 4‒6 h, with free access to food and water. Core body temperature was measured with a rectal probe attached to a TH-8 Thermalert monitoring thermometer (Physitemp Instruments Inc. Clifton, NJ). Body temperature was assessed hourly for the duration of the experiment. For humane consideration required by IACUC policy, the experiment was aborted when a temperature lower than 25°C detected in the mice.

Whole body composition was monitored using Echo MRI-100 whole-body composition analyzer (Echo Medical Systems, Houston, TX, USA) to assess fat and lean mass. All metabolic parameters data were obtained using an Oxymax (Columbus Instruments, Columbus, OH, USA) open-circuit indirect calorimetry system, as we have previously described [11 (link),71 (link)]. Mice were individually housed in feeding chambers and given free access to powdered diets for 4 days for initial acclimatization, then transferred to metabolic chambers for indirect calorimetry testing for 5 days. Data presented are averages of the day 2 to 4 of indirect calorimetry recordings. On the last day, the mice were fasted starting from 6 a.m. (light on) to 6 a.m. the following day (24 h fast). Resting metabolic rate (RMR) was calculated from the average of the 3 lowest points of energy expenditure values between 10 a.m. to 2 p.m. during the fasting period. Energy expenditure data was normalized to both lean mass and body weight. Locomotor activity was measured on x- and z-axes (horizontal and vertical activities, respectively) using infrared beams to count the number of beam breaks during the recording period.