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Adaptive effects of the β2-agonist clenbuterol on expression of β2-adrenoceptor mRNA in rat fast-twitch fiber-rich muscles
- Source :
- The Journal of Physiological Sciences. 60:119-127
- Publication Year :
- 2009
- Publisher :
- Springer Science and Business Media LLC, 2009.
-
Abstract
- Administration of the beta(2)-agonist clenbuterol has been shown to reduce the expression of beta(2)-adrenoceptor (AR) mRNA in fast-twitch fiber-rich (extensor digitorum longus, EDL) muscle without changing that in slow-twitch fiber-rich (soleus, SOL) muscle in rats. However, the regulatory mechanism for muscle fiber type-dependent down-regulation of the expression of beta(2)-AR mRNA induced by clenbuterol is still unclear. Therefore, mRNA expression of transcriptional and post-transcriptional regulatory factors for beta(2)-AR mRNA levels in fast-twitch fiber-rich (EDL and plantaris, PLA) and slow-twitch fiber-rich (SOL) muscles in clenbuterol-administered (1.0 mg/kg body weight/day for 10 days, subcutaneous) rats was studied by real-time reverse transcription-polymerase chain reaction. Administration of clenbuterol significantly reduced expression of beta(2)-AR mRNA in EDL and PLA muscles without changing that in SOL muscle. Administration of clenbuterol also significantly reduced the mRNA expression of transcriptional regulatory factor (glucocorticoid receptor) and mRNA stabilizing factor (Hu antigen R) in EDL and PLA muscles without changing those in SOL muscle. These results suggest that muscle fiber type-dependent effects of clenbuterol on expression of beta(2)-AR mRNA are closely related to the down-regulation of mRNA expression of transcriptional and post-transcriptional regulatory factors for beta(2)-AR mRNA levels.
- Subjects :
- Male
medicine.medical_specialty
Fast twitch muscle
Physiology
Rats, Sprague-Dawley
Glucocorticoid receptor
Internal medicine
medicine
Animals
Clenbuterol
RNA, Messenger
Fiber
Cells, Cultured
Messenger RNA
β2 agonists
Chemistry
musculoskeletal, neural, and ocular physiology
Adrenergic beta-Agonists
musculoskeletal system
Adaptation, Physiological
Rats
Endocrinology
Gene Expression Regulation
Mrna level
Receptors, Adrenergic, beta-3
Muscle Fibers, Fast-Twitch
β2 adrenoceptor
medicine.drug
Subjects
Details
- ISSN :
- 18806562 and 18806546
- Volume :
- 60
- Database :
- OpenAIRE
- Journal :
- The Journal of Physiological Sciences
- Accession number :
- edsair.doi.dedup.....b6b25cce2c495891802eb959e0ede4b9