CARDIOVASCULAR JOURNAL OF AFRICA • Vol 23, No 8, September 2012
AFRICA
451
Role of four-week resistance exercise in preserving the
heart against ischaemia–reperfusion-induced injury
YOUSEF DOUSTAR, FARHAD G SOUFI, AFSHAR JAFARY, MOHADDESEH M SABER, RAFIGHEH GHIASSIE
Abstract
Objective:
We studied the cardioprotective effect of resistance
training against ischaemia–reperfusion-induced injury.
Methods:
Forty male rats were divided into trained and
sedentary groups (
n
=
20
for each). The trained rats were
exercised at 12 repetitions/set, four sets/day and five days/
week for four weeks. Transient regional ischaemia of the left
anterior descending coronary artery (40 min) was followed
by 80 min of reperfusion.
Results:
Baseline developed and diastolic pressures and
coronary flow were similar in the two groups.While diastolic
pressure increased and developed pressure and coronary
flow decreased in both the ischaemic and perfusion periods
(
as indices of cardiac damage), there were no statistically
significant differences between the trained and sedentary
groups in these parameters. Resistance training did not
significantly change the infarct size and apoptosis rate.
Conclusion:
We did not see a cardioprotective effect of resist-
ance exercise against ischaemia–reperfusion-induced injury
in this study.A precise conclusion about this issue needs more
investigations.
Keywords:
exercise, heart, infarction, ischaemia, reperfusion
Submitted 27/2/11, accepted 8/6/12
Cardiovasc J Afr
2012;
23
: 451–455
DOI: 10.5830/CVJA-2012-050
Ischaemic heart disease remains a worldwide problem affecting
all economic groups of society.
1
The primary pathological
manifestation of ischaemic heart disease is myocardial infarction
due to ischemia–reperfusion (IR) injury.
2
Preservation of cardiac
performance and reduction of infarct size are the main goals in the
management of IR-induced complications.
2
In this regard, many
approaches to providing cardioprotection against IR-induced
injury have been studied.
Until now, regular exercise has been confirmed as a pragmatic
and sustainable countermeasure for cardioprotection.
3
While
convincing evidence indicates that both short-term (three to five
consecutive days) and long-term (months) endurance exercise
training (i.e. running and swimming) improves myocardial
tolerance to IR-induced injury in both male and female animals
as well as young and old animals,
3
there is no clear understanding
of the cardioprotective effect of resistance exercise training (such
as body building and weight lifting) against IR-induced injury.
Resistance exercise training is a specialised method
of conditioning designed to increase strength and muscle
endurance.
4
Similar to endurance training, it has been shown that
resistance training has beneficial effects on some physiological
and pathological processes such as physical fitness, quality of
life and chronic heart failure.
5
While the risk of cardiovascular
complications is the primary concern with resistance training in
some cardiac patients (due to blood pressure elevation during
this type of exercise), resistance training can positively influence
quality of life, cardiovascular risk factors and cardiovascular
function in healthy persons and in selected patients with
cardiovascular disease.
5,6
Although several investigators have studied the impact
of resistance training on cardiac structure and function, the
cardioprotective effect of resistance exercise training against
IR-induced injury has not been understood. The purpose of
this study was to investigate cardiac performance during the
ischaemic and reperfusion periods, as well as to determine
cardiac infarct size and apoptosis rate after IR-induced injury in
rats undergoing resistance exercise training for a short period of
four weeks.
Methods
Forty male Wistar rats (220–240 g, three months old) were
obtained from the laboratory animal house of Tabriz University
of Medical Sciences and they were randomly divided into trained
(
EXT) and sedentary (Sed) groups (
n
=
20
for each group).
Animals were housed at room temperature (23
±
1
°C) with
12-
hour light/dark cycles and had free access to food and water.
The study protocol was designed in accordance with the
Guide
for the Care and Use of Laboratory Animals
published by the
US National Institutes of Health (NIH publication, revised 1996)
and approved by the Ethics Committee for the Use of Animals in
Research of the Tabriz University of Medical Sciences.
Trained rats were exercised according to the model described
by Tamaki
et al
.,
with some modifications.
7
Rats were placed
vertically in a squat-training apparatus cylinder (RatWLI009,
Tajhiz Azmaye Pooya Co, Iran) as they could stand on their hind
limbs in response to electrical stimulation and raise the piston
which was located above their heads. An electrical stimulation
(20
V, 0.3-s duration at 3-s intervals) was applied to the rat’s tail
through a surface electrode. After one week of adaptation, the
trained group of rats exercised for four sets of 12 repetitions per
Department of Pathology, Faculty of Veterinary Medicine,
Islamic Azad University (Tabriz branch), Tabriz, Iran
YOUSEF DOUSTAR, MD,
Drug Applied Research Centre, Tabriz University of Medical
Sciences and Department of Physiology, Faculty of
Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
FARHAD G SOUFI, PhD
Department of Exercise Physiology, Faculty of Physical
Education, Tabriz University, Tabriz, Iran
AFSHAR JAFARY, PhD
Drug Applied Research Centre, Tabriz University of Medical
Sciences, Tabriz, Iran
MOHADDESEH M SABER, MSc
RAFIGHEH GHIASSIE, MSc
