著者

Nao Akiyama Yoshiki Ohnuki Yuki Kunioka Yasutake Saeki Takenori Yamada

出版者

日本生理学会

雑誌

The Journal of Physiological Sciences (ISSN:18806546)

巻号頁・発行日

vol.56, no.2, pp.145-151, 2006 (Released:2006-07-30)

参考文献数

28

被引用文献数

20 35

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The transverse stiffness of single myofibrils of skeletal and cardiac muscles was examined by atomic force microscopy. The microscopic images of both skeletal and cardiac myofibrils in a rigor state showed periodical striation patterns separated by Z-bands, which is characteristic of striated muscle fibers. However, sarcomere patterns were hardly distinguishable in the stiffness distributions of the relaxed myofibrils of skeletal and cardiac muscles. Myofibrils in a rigor state were significantly stiff compared with those in a relaxed state, and in each state, cardiac myofibrils were significantly stiffer compared with skeletal myofibrils. By proteolytic digestions of sarcomere components of myofibrils, it was suggested that cardiac myofibrils are laterally stiffer than skeletal myofibrils because Z-bands, connectin (titin) filament networks, and other components of sarcomere structures for the former myofibrils are stronger than those for the latter.