尾部懸垂によるラットヒラメ筋におけるミオシンアイソフォームの分布の変化

EFFECTS OF HINDLINB SUSPENSION ON PATTERNS OF MYOSIN ISOFORMS IN RAT SOLEUS MUSCLE

Okumoto Tadashi

Saitoh Ayako

Katsuta Shigeru

Niihata Shigemitsu

Kikuchi Kunio

Wada Masanobu

体力科学 : Japanese Journal of Physical Fitness and Sports Medicine

Using several electrophoretic techniques, this study examined the efeicts of 3 weeks hindlimb suspension on the patterns of isomyosins, myosin heavy chain(HC)isoforms and myosin light chain (LC)isoforms in the soleus muscle of the rat. The suspended soleus showed a shift in the HC isoform distribution with a marked increase in fast HC isoforms and a commensurate decrease in HCI. In addition, the change in the fast HC isoforms consisted of the expression of HCIId and HC IIb absent in the normal soleus. In contrast to HC isoforms, suspension did not lead to appreciable changes in LC isoform distribution. Analyses of electrophoresis under nondenaturing conditions demonstrated that the normal soleus expressing HCI and HCIIa isoforms contained two isomysoins. Although, of the two isomyosins observed in the normal soleus, the faster migrating band most likely represented the HCIIa-based one(FMas), its mobility was not identical with that of the HCIIa-based isomyosin(FMaf)found in fast-twitch muscles, migrating in the order FMaf>FMas. FMas was designated as intermediate isomyosin(IM). Some of the suspended soleus contained slow isomyosin(SM)and IM whereas the others comprised FM3 and/or FM2 as well as SM and IM. In spite of the expression of HCIIb and HCIId in the suspended soleus, FM3 and FM2 observed in these muscles exhibited distinct mobilities from either HCIId-based or HCIIb-based isomyosins comprised in fast-twitch muscles. These results suggest that some of newly expressed HCIId and /or HCIIb isoforms in the suspoended soleus are associated with not only fast but also slow LC isoforms and function as a constitutive elemet of the myosin molecule.

hindlimb suspension

isomyosins

myosin heavy chain isoforms

myosin light chain isoforms

Medical sciences [ 490 ]

jpn

日本体力医学会

日本体力医学会

本文データは学協会の許諾に基づきCiNiiから複製したものである

[ISSN] 0039-906X

[NCID] AN00137986

[NAID] 110001917967