Abstract
Ghrelin and agouti-related protein (AgRP) are orexigenic peptides secreted from stomach
mucosa and the arcuate nucleus of the hypothalamus, respectively. Both peptides affect
feeding behavior and play a role in energy balance, glucose homeostasis, and adiposity.
The purpose of the current study was to determine the effects of moderate-term (6
weeks) running regimen on resting levels of ghrelin, AgRP, adenosine triphosphate,
and glycogen in soleus muscle as well as plasma concentrations of the orexigenic hormones.
Eighteen adult Wistar male rats (12 weeks old, 235-255 g) were randomly assigned to
training (n = 10) and control (n = 8) groups. The training group ran for 60 min/d,
5d/wk at 25 m/min and 0% grade for 6 weeks. Forty-eight hours after the last exercise
session, rats were killed; and soleus muscle and plasma were collected and frozen
in liquid nitrogen for later analysis. Results demonstrated that 6 weeks of treadmill
exercise reduced ghrelin and increased AgRP levels in plasma. Trained rat soleus muscle
had higher levels of glycogen but not adenosine triphosphate or AgRP compared with
untrained controls. Data indicate that training lowers ghrelin levels in rat soleus
and plasma, which is accompanied by higher plasma AgRP and soleus glycogen content.
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Article info
Publication history
Published online: July 27, 2009
Accepted:
June 16,
2009
Received:
April 29,
2009
Footnotes
All experiments involving the animals were conducted according to the policy of the Iranian Convention for the Protection of Vertebrate Animals Used for Experimental and Other Scientific Purposes; and the protocol was approved by the Ethics Committee of the School of Medical Sciences, Tarbiat Modares University, Tehran, Iran.
Identification
Copyright
© 2009 Elsevier Inc. Published by Elsevier Inc. All rights reserved.
