Treadmill exercise's reduction of Agouti-related protein expression in rat liver.
Agouti-related protein (AGRP) is an orexigenic peptide secreted from the arcuate nucleus (ARC) of the hypothalamus. AGRP increases food intake and plays a role in energy balance, adiposity, weight gain, and growth-hormone release. The objective of the current study was to examine the effects of running exercise on resting hepatic, fundus, and pancreas AGRP mRNA expression, as well as liver glycogen and ATP contents, using a rat model. Twenty adult male Wistar rats (12-14 wk old, 200-220 g) were randomly assigned to control (n = 10) and training (n = 10) groups. The training group was exercised for 8 wk on a motor-driven treadmill (26 m/min, 0% grade, 60 min, 5 d/wk). Twenty-four hours before sacrifice the rats were further divided into fed control (FEC), fed trained (FET), fasted control (FAC), and fasted trained (FAT) groups. The liver, fundus, and pancreas were excised and frozen in liquid nitrogen for later analysis. Results demonstrated that 8 wk of treadmill exercise reduced hepatic but not fundus and pancreatic AGRP expression and enhanced glycogen and ATP concentrations (p < .001) in trained-rat liver, whereas fasting lowered liver glycogen and ATP levels and increased hepatic AGRP mRNA expression in nonexercising controls. Data indicate that both treadmill-exercise-induced decrease and fast-induced increase in rat liver AGRP expression might depend on liver glycogen content as an important source for energy provision.
Ghanbari-Niaki
Abbass
A
Faculty of Physical Education and Sports Sciences, University of Mazandaran, Baboulsar, Mazandaran, Iran.
Fathi
Rozita
R
Kakhak
Sayed Alireza Hossaini
SA
Farshidi
Zhara
Z
Barmaki
Sara
S
Rahbarizadeh
Fatemeh
F
Kraemer
Robert R
RR
D000255:Adenosine Triphosphate / Q000378:metabolism; D054369:Agouti-Related Protein / Q000378:metabolism*; D000818:Animals; D004435:Eating / Q000502:physiology; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test; D005215:Fasting / Q000502:physiology*; D005748:Gastric Fundus / Q000378:metabolism; D015870:Gene Expression / Q000502:physiology; D006801:Humans; D008099:Liver / Q000378:metabolism*; D008112:Liver Glycogen / Q000378:metabolism; D008297:Male; D023421:Models, Animal; D010179:Pancreas / Q000378:metabolism; D010805:Physical Conditioning, Animal; D019518:Postprandial Period / Q000502:physiology*; D012333:RNA, Messenger / Q000032:analysis / Q000378:metabolism; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar
C515197:AGRP protein, rat; D054369:Agouti-Related Protein; D008112:Liver Glycogen; D012333:RNA, Messenger; D000255:Adenosine Triphosphate