Ohira Yoshinobu, Kawano Fuminori, Goto Katsumasa, Wang Xiao Dong, Takeno Yoshiaki, Ishihara Akihiko
Sch. Health Sport Sci, Osaka Univ.
Biol Sci Space. 2004 Nov;18(3):124-5.
Effects of hindlimb suspension or exposure to 2-G between postnatal day 4 and month 3 and of 3-month recovery at 1-G environment on the characteristics of rat hindlimb muscles were studied. Pronounced growth inhibition was induced by unloading, but not by 2-G loading. It is suggested that the development and/or differentiation of soleus muscle fibers are closely associated with gravitational loading. The data indicated that gravitational unloading during postnatal development inhibits the myonuclear accretion in accordance with subnormal numbers of both mitotic active and quiescent satellite cells. Even though the fiber formation and longitudinal fiber growth were not influenced, cross-sectional growth of muscle fibers was also inhibited in association with lesser myonuclear domain and DNA content per unit volume of myonucleus. Unloading-related inhibition was generally normalized following the recovery.
研究了出生后第4天至3个月期间后肢悬吊或暴露于2-G环境以及在1-G环境中恢复3个月对大鼠后肢肌肉特征的影响。卸载可导致明显的生长抑制，而2-G加载则不会。提示比目鱼肌纤维的发育和/或分化与重力负荷密切相关。数据表明，出生后发育期间的重力卸载会抑制肌核增殖，同时有丝分裂活跃和静止卫星细胞的数量均低于正常水平。尽管纤维形成和纵向纤维生长未受影响，但肌纤维的横截面积生长也受到抑制，这与较小的肌核域和每单位体积肌核的DNA含量有关。恢复后，与卸载相关的抑制作用通常会恢复正常。
