McMullan4 project protocol

Body weight and composition after voluntary exercise in females of 13 Collaborative Cross strains of mice   (2018)

McMullan RC, Pardo-Manuel de Villena F
With: Ferris MT, Bell TA, Menachery VD, Baric RS, Hua K, Pomp D, Smith-Ryan AE

Project protocol - Contents

Workflow and sampling

Data collected
Weigh mice Scales
Body weight
2 Assess body composition before and after treatment
MRI Lean mass and fat mass
3 Measure wheel running activity and food intake Running wheel and software Distance, duration, speed on the running wheel; food intake

Equipment and supplies

  • Running wheels (1.1 m circumference; Lafayette Industries, Lafayette IN)
  • Whole body MRI (EchoMRI 3-in-1 Body Composition Analyzer, EchoMRI, Houston TX)
  • Activity wheel monitoring program (AWM, Lafayette Industries, Lafayette IN)

Reagents and solutions

  • Disinfectant

Procedure: Wheel running activity

  1. Mice in the experimental cohort are individually housed in standard laboratory cages with ad libitum access to attached running wheels (mice in the control cohort are group housed if possible).
  2. Distance (total revolutions x 1.1 m), duration (cumulative 1-min intervals in which at least 1 revolution is recorded), and average speed (total distance/total duration) are recorded for a 2-wk period.

Procedure: Body composition and food intake

  1. Body composition is assessed during mornings 0700-1200h using whole body MRI to determine fat and lean mass content for each animal.
  2. Body mass and composition are measured immediately prior to the start of the experiment and at the conclusion of the experiment.
  3. Body fat and lean mass percentages are calculated relative to body mass at each time point in every experiment. Body mass and composition responses for both cohorts are calculated for the two weeks of treatment. Body mass response is calculated as [(Post-mass – pre-mass)/pre-mass] x 100. Body composition percentage response is calculated as [(post-measurement % - pre-measurement %)/pre-measurement %] x 100.
  4. Food is weighed prior to and after the experiment for the experimental cohort (food intake for the control cohort is not tracked as these mice are group housed). Adjusted food intake is calculated as the food intake relative to the baseline body mass for the experimental cohort.

Data collected by investigator

  • Body weight and body weight response
  • Body composition
    • Fat percentage and response
    • Lean percentage and response
  • Wheel running activity
  • Food intake