尾吊大白鼠比目鱼肌特性动态变化过程观察

Observation of Dynamic Changes of Rat Soleus During Tail Suspension

本文报告了用尾吊法模拟失重观察大白鼠比目鱼肌在悬吊过程中肌肉重量、蛋白质绝对含量及肌肉生物力学特性的动态变化。悬吊鼠分为3、7、13、21、30天5个组。肌肉重量和蛋白质绝对含量在悬吊初期下降,以后又逐渐回升,其变化规律都可用多项式表达。肌重、蛋白质绝对含量和力学特性的变化反映了悬吊引起的低运动/低动力导致肌肉废用性萎缩,但萎缩程度并不随悬吊时间的延长而相应地加重,在悬吊后期各参数值有回升现象。根据上述现象,可以认为比目鱼肌重量、蛋白质绝对含量、肌张力三者之间密切相关;同时,大白鼠经两周尾吊其后肢肌肉即可出现明显萎缩,可为今后悬吊时间的选择提供依据;肌肉等长单收缩的收缩时间与半松弛时间逐渐缩短,可能反映了慢肌向快肌的转化。

The purpose of this study was to observe the dynamic changes of rat's soleus muscle after different periods of tail suspension. The weight of soleus, total protein absolute content and biomechanical parameters were determined. The rats were divided into five groups of 3, 7, 13, 21, and 30 days suspension respectively. The weight and total protein absolute content of soleus decreased in the early days of suspension, then increased gradually. Their regularity could be expressed with multinomials. The changes of weight, total, protein absolute content and biomechanical properties of soleus suggested that hypokinesia/hypodynamia caused atrophy of soleus. The degree of atrophy didn't increase with duration of suspension, but showed some recovery during the later period. According to the above mentioned phenomena, it might be considered that there was close relationship among soleus weight, total protein absolute content and muscle contraction tension. The atrophy of soleus appeared significantly after 2—week tail suspension, this might serve as a basis for the selection of duration of suspension in further studies. The contraction time and half relaxation time of isometric single twitch of soleus decreased gradually after suspension, which probably indicated that there was conversion of slow twitch fibres to the fast ones.