小鼠肺內支氣管肌肉之電子顯微鏡研究   全文下載

The Intrapulmonary Airway Smooth Muscle of Mice an Ultrastructural Study

本研究是以穿透式電子顯微鏡來觀察小鼠肺內支氣管平滑肌肉細胞之細微構造，小鼠肺內支氣管肌肉細胞之細構造與其他動物氣管或其他組織的平滑肌肉細胞相類似。平滑肌肉細胞成環狀排列圍繞於支氣管外側，細胞形狀為長條梭形，彼此之間依長軸平行排列，細胞核為長橢圓形，位於細胞中央最寬大處，經過細胞核之細胞橫切面的直徑約4.6μm，其他胞器如線粒體、內質網膜、高氏體及微管等都可觀察到。關於平滑肌肉細胞之收縮纖維目前只見到直徑約5nm之肌動蛋白絲，及直徑約10nm之中間型纖維，並未發現最粗的肌凝蛋白絲，緻密體、緻密帶及肌肉膜泡的構造皆與其他平滑肌肉細胞相似。在電子顯微鏡下可分辨出三種細胞連合情形：間隙連合構造、中間型連合構造及手指狀突起。

The fine structure of intrapulmonary airway smooth muscle of mice was studied by transmission electron microscopy. The fine structure of bronchial smooth muscle cells is similar to that of trachea of other mammals and similar to that of other organs. The smooth muscle cells surround the bronchus like a ring. They are arranged parallel to each other along their long axis. The nueleus is oval in shape and locate in the widest part of the cell. The diameter of the cell profile cutting through the nucleus was about 4. 6 urn. Other organelles such as mitochondria, endoplasmic reticulum, Golgi apparatus and microtubules were also examined. Only one type of contractile filaments of smooth muscle cells could be observed. The diameter of these actin filaments was about 5 nm. Another type of filaments, the intermediate filaments was found to have a diameter of 10 nm. The structure of dense bodies, dense bands and cavaeolae was similar to that of the smooth muscle cells of other organs. Three kinds of cell junctions were distinguished by electron microscopy in this study. These were the gap junctions, the intermediate junctions and the finger-like processes.