Role of Masseter Muscle β2-Adrenergic Signaling in Regulation of Muscle Activity, Myosin Heavy Chain Transition, and Hypertrophy

Journal of Pharmacological Sciences

Wenqian Cai⁴  Yasutake Saeki²  Yasumasa Mototani²  Satoshi Okumura²  Takayuki Fujita⁴  Yoshiki Ohnuki²  Hui-Ling Jin⁴  Daisuke Umeki³  Eiji Tanaka¹  Kouichi Shiozawa²  Nobuhiko Kawai¹ 

[1] Department of Orthodontics and Dentofacial Orthopedics, Institute of Health Biosciences, The University of Tokushima Graduate School of Oral Sciences, Japan;Department of Physiology, Tsurumi University School of Dental Medicine, Japan;Department of Orthodontics, Tsurumi University School of Dental Medicine, Japan;Cardiovascular Research Institute, Yokohama City University Graduate School of Medicine, Japan

关键词: β2-adrenergic signaling;    masseter muscle;    electromyogram;    myosin heavy chain;    hypertrophy;   

DOI  :  10.1254/jphs.12271FP

学科分类：药学

来源: Nihon Yakuri Gakkai Henshuubu / Japanese Pharmacological Society

【 摘 要 】

References(54)Cited-By(5)Supplementary materials(1)Chronic administration of clenbuterol (CB), a lipophilic β2-adrenoceptor (β2-AR) agonist, induces skeletal muscle hypertrophy and slow-to-fast fiber–type transitions in mammalian species, but the mechanism and pathophysiological roles of these changes have not been explored. Here, we examined the effects of CB not only on masseter muscle mass, fiber diameter, and myosin heavy chain (MHC) composition, but also on daily muscle activity, a factor influencing muscle phenotype, by means of electromyogram analysis in rats. MHC transition towards faster isoforms was induced by 2-week CB treatment. In addition, daily duty time was increased at 1 day, 1 week, and 2 weeks after the start of CB treatment and its increase was greater at high activity level (6-fold) than at low activity level (2-fold). In order to examine whether these effects of CB were mediated through muscle or CNS β2-AR stimulation, we compared these effects of CB with those of salbutamol (SB), a hydrophilic β2-AR agonist. SB treatment induced masseter hypertrophy and MHC transition, like CB, but did not increase daily activity. These results suggest that CB-mediated slow-to-fast MHC transition with hypertrophy was induced through direct muscle β2-AR stimulation, but the increase of daily duty time was mediated through the CNS.[Supplementary Figures: available only at http://dx.doi.org/10.1254/jphs.12271FP]

【 授权许可】

Unknown