Effects of Clenbuterol and Cyclosporin A on the Myosin Heavy Chain mRNA Level and the Muscle Mass in Rat Masseter
| Autor: | Daisuke Umeki, Yoshiki Ohnuki, Yasutake Saeki, Chihiro Arai, Ayao Hirashita |
|---|---|
| Rok vydání: | 2006 |
| Předmět: |
medicine.medical_specialty
Physiology Calcineurin Inhibitors Muscle Fibers Skeletal Muscle hypertrophy Masseter muscle Internal medicine Cyclosporin a MHC class I Gene expression Myosin medicine Animals Clenbuterol RNA Messenger Enzyme Inhibitors Rats Wistar Myosin Heavy Chains biology Masseter Muscle Chemistry Calcineurin Organ Size Adrenergic beta-Agonists Rats Endocrinology Gene Expression Regulation Biochemistry Cyclosporine biology.protein Signal Transduction medicine.drug |
| Zdroj: | The Journal of Physiological Sciences. 56:205-209 |
| ISSN: | 1880-6562 1880-6546 |
| DOI: | 10.2170/physiolsci.rp002206 |
| Popis: | To gain more insight into the molecular mechanism of muscle growth and fiber-type transformations, we analyzed the effects of beta(2)-adrenergic agonist clenbuterol (CB) and/or cyclosporin A (CsA), a potent inhibitor of calcineurin (CaN), on the muscle mass as well as on the mRNA levels of myosin heavy chains (MHC I, IIa, IId/x, IIb), using a real-time RT-PCR with specific primers in rat masseter. In comparison with control, the CB treatment significantly decreased the MHC I mRNA level (p < 0.01), but increased the MHC IId/x mRNA level (p < 0.01), and the CsA treatment significantly decreased the MHC I mRNA level (p < 0.05) in association with the significant decrease in MHC IIb mRNA level (p < 0.05). The CB+CsA treatment significantly decreased the levels of MHC I (p < 0.01) and IIa mRNAs (p < 0.05), but increased the MHC IId/x mRNA level (p < 0.001) in association with a significant decrease in MHC IIb mRNA level (p < 0.01), in comparison with control. The masseter muscle mass was significantly (p < 0.001) increased by either the CB or the CB + CsA treatment, but decreased with the CsA treatment (p < 0.01). These results suggest that in rat masseter muscle, CB has an anabolic action accompanying MHC mRNA I IIa IId/x sequence transition independently of CaN-signaling pathways, and CaN is involved in the type I fiber gene expression and the muscle mass maintenance of type IIb fiber. |
| Databáze: | OpenAIRE |
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