Alnaqeeb M A, Al Zaid N S, Goldspink G
J Anat. 1984 Dec;139 ( Pt 4)(Pt 4):677-89.
Selective staining of the connective tissue and image analysis showed that in the extensor digitorum longus and soleus muscles of the rat there was an increase in the thickness of the endomysium in both early growth and senility. The perimysium thickness was more or less constant throughout life except in senility when the concentration of this component also increased. The stiffness (length-passive tension) of these muscles was found to increase throughout life. Log transforms of the length-passive tension plots had particularly steep slopes in the senile extensor digitorum longus muscle. Except in the senile soleus muscle, the increase in stiffness was closely correlated with the increase in endomysium and perimysium and with total muscle collagen (as measured biochemically) with age. The relationship between the initial length and the active tension in the extensor digitorum longus muscle changed with age. The older muscles showed a greater decline in tension for each decrement of length resulting from the increased development of the connective tissue.
结缔组织的选择性染色和图像分析表明，在大鼠的趾长伸肌和比目鱼肌中，肌内膜厚度在生长早期和衰老期均增加。肌束膜厚度在整个生命过程中或多或少保持恒定，但在衰老期，该成分的浓度也会增加。这些肌肉的僵硬度（长度-被动张力）在整个生命过程中都有所增加。在衰老的趾长伸肌中，长度-被动张力曲线的对数转换具有特别陡峭的斜率。除了衰老的比目鱼肌外，僵硬度的增加与肌内膜和肌束膜的增加以及随着年龄增长的总肌肉胶原蛋白（通过生化测量）密切相关。趾长伸肌的初始长度与主动张力之间的关系随年龄而变化。由于结缔组织发育增加，每减少一定长度，较老的肌肉张力下降幅度更大。
