Role of local muscle contractile activity in the exercise-induced increase in NR4A receptor mRNA expression
Autor: | Emi Kawasaki, Keiichi Koshinaka, Atsushi Sakai, Maiko Sasaki, Fumi Hokari, Kentaro Kawanaka |
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Rok vydání: | 2009 |
Předmět: |
Male
medicine.medical_specialty Receptors Steroid Nerve growth factor IB Physiology Physical exercise Nerve Tissue Proteins Biology Running AMP-Activated Protein Kinase Kinases Physiology (medical) Internal medicine Physical Conditioning Animal Gene expression medicine Nuclear Receptor Subfamily 4 Group A Member 1 Animals RNA Messenger Rats Wistar Receptor Muscle Skeletal Swimming chemistry.chemical_classification Fatty acid Skeletal muscle Adenosine Electric Stimulation Rats Up-Regulation DNA-Binding Proteins Enzyme medicine.anatomical_structure Endocrinology chemistry Hindlimb Suspension Protein Kinases Glycogen medicine.drug Muscle Contraction |
Zdroj: | Journal of applied physiology (Bethesda, Md. : 1985). 106(6) |
ISSN: | 8750-7587 |
Popis: | Exercise upregulates the expression of NR4A receptors, which are involved in regulation of glucose and fatty acid utilization genes in skeletal muscle. The aims of our study were 1) to determine the role of local contractile activity on NR4A mRNA expression in skeletal muscle during exercise; and 2) to elucidate the mechanisms underlying the induction of NR4A mRNA expression in response to muscle contractile activity. Rats were subjected to an acute 3-h low-intensity swimming or a 3-h low-intensity treadmill running as a model of endurance exercise. Low-intensity swimming increased NR4A1 and NR4A3 mRNA in triceps but not in soleus muscle. Conversely, low-intensity treadmill running increased NR4A1 and NR4A3 mRNA in soleus but not in triceps muscle. NR4A mRNA increased concomitantly with reduced postexercise muscle glycogen, suggesting that gene expression of NR4A receptors occurs in muscles recruited during exercise. Furthermore, in resting rats, an acute 1-h local electrical stimulation of a motor nerve to the tibialis anterior muscle caused increases in NR4A1 and NR4A3 mRNA relative to the contralateral control muscle of the same animals. On the other hand, after 6 h of hindlimb immobilization, NR4A1 and NR4A3 mRNA were reduced in immobilized soleus muscle relative to contralateral control muscle. In addition, both NR4A1 and NR4A3 mRNA in epitrochlearis muscle were increased after 6-h incubation with 0.5 mM 5-aminoimidazole-4-carboxamide-1-β-d-ribofuranoside, which activates AMP-activated protein kinase. These results suggest that 1) local muscle contractile activity is required for increased expressions of NR4A1 and NR4A3 mRNA during exercise; and 2) muscle contractile activity-induced increases in NR4A1 and NR4A3 mRNA may be mediated by AMPK activation, at least in part. |
Databáze: | OpenAIRE |
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