Animal models are routinely used to study obesity and the associated metabolic disorders. One of the
most commonly used models, is the diet-induced obese (DIO) mouse. This is a simple model, where the
animals are made obese through feeding a high fat diet (HFD). Once obese, animals begin to develop a
number of metabolic diseases, similar to those seen in humans.
During this practical you will dissect male and female mice that have been made obese by feeding a HFD
for 12 weeks. Control or lean animals have been maintained on a chow diet. The objective of this
practical is to:
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Become familiar with a commonly used mouse model of obesity and understand why obesity develops in
these mice.
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Characterise the blood glucose and lipid profile of obese mice.
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Identify major internal organs and understand which respond to body weight gain.
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Identify sex differences in the control of body weight and the onset of metabolic disorders.
Mouse models are widely used in the study of metabolic disease as they show many similarities to humans.
Obesity affects many organ systems in the body to ultimately cause type 2 diabetes, cardiovascular
disease, non-alcohol fatty liver disease (NAFLD) and non-alcohol steatohepatitis (NASH).
Much of what we know about the body comes from experiments using whole animals, including humans, or
tissues taken from (dead) animals. Progress in physiology depends on further experimentation.
In asserting the importance of continued experimentation, physiologists are well aware of the obligation
of all biologists to ensure that the experiments undertaken are demonstrably necessary and that
experimental animals are properly looked after and treated humanely at all times.
The National Health and Medical Research Council (NH&MRC) of Australia, and more recently the CSIRO and
the Australian Agricultural Council, have played a prominent part in setting up standards for the care
and use of experimental animals in Australia. Biological research groups such as the Australian
Physiological and Pharmacological Society have for some time accepted these standards, embodied in a
Code of Practice for the Care and Use of Animals for Experimental Purposes, as guiding principles. The
‘General Principles for the Care and Use of Animals for Scientific Purposes' from the 2004 Code are set
out in full in the unit guide.
This simulation adheres with the principles of these guidelines by reducing unnecessary use of animals.
Whilst the dissection of the mouse is a necessary part of the practical, we have refined the
experimental approach and used the data collected over the past years in this simulation.
