Bassem M. Alsawy1,3, Magdi A. El-Damarawi2,3*
1Department of Physiology, Faculty of Medicine, Beni Swaif
University, Egypt; 2Department of Physiology, Faculty of
Medicine, Tanta University, Tanta, Egypt; 3On Sabbatical leave to
Department of Physiology, Faculty of Medicine, University of Tabuk, Saudi
Arabia
AIM: This work was done to study the effect of both types of diabetes
mellitus (DM) on myocardial contractility in rats. Also, we investigated the
role of treatment of DM with insulin and rosiglitazone (used as treatment
for type 1 and type 2 DM respectively) in improvement of myocardial
dysfunction in diabetic rats.
METHODS: The study included 50 male Wistar albino rats, divided into
5 groups: control (group I), streptozotocin induced type 1 DM (group II),
fructose induced type 2 DM (group III), insulin treated type 1 diabetic rats
(group IV) and rosiglitazone treated type 2 diabetic rats (group V). At the
end of the study, retro-orbital blood samples were withdrawn and blood
glucose, plasma triglyceride (TG), total cholesterol (TC) and thyroid
hormones levels were measured. Rats were then anesthetized and their hearts
were excised and connected to Langendorff apparatus to perform mechanical
cardiac performance tests including heart rate (HR), left ventricular
developed pressure (LVDP) and maximum rate of pressure rise (+dp/dt).
RESULTS: Data of the study showed that relative to control group,
there was significant increase in blood glucose, plasma TG and TC levels
while, thyroid hormones and myocardial performance parameters showed
significant decrease in both type 1 and type 2 diabetic rats. Treatment of
type 1 diabetic rats with insulin and type 2 with rosiglitazone resulted in
significant decrease in blood glucose, plasma TG and TC levels associated
with significant improvement in thyroid hormones and myocardial performance
parameters. The results also showed that insulin treatment of type 1 was
more effective in ameliorating all parameters than treatment of type 2 by
rosiglitazone.
CONCLUSION: We concluded that the induction of both types of diabetes
resulted in decreased myocardial performance parameters. The treatment of
type 1 and type 2 diabetes by insulin and oral rosiglitazone respectively
improved to a great extent the altered metabolism and mechanical myocardial
parameters, with more improving effect of insulin in type 1 than
rosiglitazone in type 2 DM.
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Citation: Alsawy BM, El-Damarawi MA. Effect of
Diabetes Mellitus and Its Control on Myocardial Contractile Function in
Rats. Maced J Med Sci. 2014 Sep 15; 7(3):431-438. http://dx.doi.org/10.3889/MJMS.1857-5773.2014.0426.
Key words: Diabetes mellitus; Thyroid dysfunction; Diabetic
cardiomyopathy; Insulin; Rosiglitazone.
*Correspondence: Dr. Magdi Ali El-Damarawi. Tanta University,
Physiology, Tanta 12345, Egypt. Phone: 00201003889807. E-Mail: magdidamarawi@yahoo.com
Received: 13-May-2014; Revised: 20-Jun-2014; Accepted: 30-Jun-2014; Online
first: 19-Jul-2014
Copyright: © 2014 Alsawy & El-Damarawi. This is an open access
article distributed under the terms of the Creative Commons Attribution
License, which permits unrestricted use, distribution, and reproduction in
any medium, provided the original author and source are credited.
Competing Interests: The authors have declared that no competing
interests exist.
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