McMullan3 project protocol

Body composition responses following voluntary exercise in aging females of 43 Collaborative Cross strains of mice   (2017)

McMullan RC, Pomp D, Pardo-Manuel de Villena F

Project protocol - Contents

Workflow and sampling

Data collected
Voluntary wheel running Standard laboratory cages with attached running wheels
2 Weigh mice
Scales Body weight
3 Assess body composition MRI Lean mass, fat mass
4 Determine food intake Scales Food intake

Equipment and supplies

  • Scales
  • Whole body MRI (EchoMRI 3-in-1 Body Composition Analyzer, EchoMRI, Houston TX)

Reagents and solutions

  • Disinfectant

Procedure: Body weight and body composition

  1. Mice are weighed prior to MRI.
  2. Body composition is assessed using whole body MRI prior to the start of the experiment, mid experiment (2 wks) and at the end of the experiment (4 wks).
  3. All measurements are collected between 0700 and 1200h.
  4. Fat mass and lean mass percentages are calculated relative to body weight.
  5. Three responses are calculated: response 1 (wks 1-2), response 2 (wks 3-4), and total response (from start to 4 wks).
  6. Response = [((Post percentage - Pre percentage)/Pre percentage) * 100]

Procedure: Food intake

  1. Food is weighed at the beginning and end of the time period for wks 1-2 and wks 3-4.
  2. Food intake is calculated as [Pre food weight – post food weight].

Data collected by investigator

  • Body weight
  • Body composition
    • Fat percentage
    • Lean percentage
  • Responses (changes)
    • Body weight over time
    • Fat percentage over time
    • Lean percentage over time
  • Food intake