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3.2.3 Wheel Running
In contrast to treadmill and swimming, wheel running is voluntary exercise. Voluntary
wheel running is usually adopted to examine chronic exercise in rodent species. It
involves the use of running wheels manufactured with stainless steel and plastic
(Fig. 4.1b) or the use of an angled rotating running track (Fig. 4.1c) [ 17 ]. Animals
will spontaneously start running if given access to a freely rotating wheel [ 9 , 48 ]. This
spontaneous exercise can be performed with minimal intervention by the investiga-
tors, is less stressful to the animals, and can be performed with varying resistance
loads as summarized in a previous review [ 11 ]. Since animals can be housed in
wheels for long periods of time with minimal disturbance, the wheel running exercise
is appropriate for aging studies [ 55 ]. Furthermore, wheel running are able to promote
physiological cardiac remodeling involving a set of microRNAs, essential in different
cellular processes in the regulation of cardiovascular phenotypes [ 55 , 56 ].
3.3 Animals in Cardiovascular Exercise Studies
Researches regarding cardiovascular physiological and pathophysiological activi-
ties are necessary for designing novel treatment options to prolong and improve
patients’ lives [ 6 ]. In fact, exercise is considered as a medicine which can prevent,
manage, and regulate numerous cardiac chronic conditions [ 41 ]. Regular physical
exercise in humans can even reduce cardiovascular risk and reduce death during
cardiovascular diseases [ 41 , 57 ]. However, the beneficial or adverse outcomes of
exercise intervention in the treatment of a specific condition should be tested before
applying in a clinical setting. Because of research ethics and technical difficulties in
humans, animal exercise models are necessary for the future development of exer-
cise mimetics in treatment of cardiovascular abnormalities [ 11 ]. In fact, animal
models are key aspects of cardiac research where a variety of cardiac pathophysiol-
ogy and therapeutic targets can be studied [ 3 , 4 , 6 , 10 , 15 , 18 , 43 ]. In cardiovascular
researches, mouse, rat, rabbit, canine, goat, horse, and sheep are commonly used,
having its own strengths and weaknesses. A suitable animal model is still required
to study cardiovascular pathophysiology efficiently in order to be reliably used for
translational applicability in humans. Despite the preservation and conservation of
many aspects of the cardiovascular system, various gaps still exist between animals
and humans which must be considered. Differences arising from variations in heart
properties and characteristics were described in detail in a previous publication [ 6 ].
3.3.1 Small Rodent Animals Used in Cardiovascular Models
Mouse or rat models possess unique properties which make them efficient models for
cardiovascular researches. Strengths such as easy handling, short gestation time, and
cost effectiveness make them suitable to be used for researches on cardiovascular
V.T. Thu et al.