2013 Fiscal Year Final Research Report
Investigation of the mechanism responsible for the modulation of myosin heavy chain expression in muscle fibers.
Project/Area Number |
24890301
|
Research Category |
Grant-in-Aid for Research Activity Start-up
|
Allocation Type | Single-year Grants |
Research Field |
Environmental physiology (including Physical medicine and Nutritional physiology)
|
Research Institution | Japan Aerospace Exploration Agency |
Principal Investigator |
OHIRA Takashi 独立行政法人宇宙航空研究開発機構, 有人宇宙ミッション本部, 宇宙航空プロジェクト研究員 (40633532)
|
Project Period (FY) |
2012-08-31 – 2014-03-31
|
Keywords | 骨格筋 / タンパク質発現調節 |
Research Abstract |
Gravitational unloading causes a shift of fiber phenotype toward fast-twitch type in soleus muscle. However some fibers are remain slow-twitch type. It has not known why the transformation of myosin heavy chain (MHC) phenotype is induced only in specific fibers expressing type I MHC originally. The current study was performed to investigate the effects of mechanical and/or neural factors on the fiber phenotype. Responses of MHC expression in soleus muscles to 2-week inhibition of mechanical activity or neural activity by hindlimb suspension or ablation of sciatic nerve respectively, were studied in rats. As a result, both experimental model was induced the increase of the type II MHC mRNA and protein expression. And the % distribution of fibers co-expressing type I and II MHC was increased. But fibers expressing pure type I MHC were still noted. It was suggested that the cause for de novo expression of type II MHC might be regulated by mechanical and neural activity and other factors.
|