胡子鲇、月鳢、泥鳅具气呼吸作用器官呼吸上皮的电镜观察

AN ELECTRON MICROSCOPIC STUDY OF THE RESPIRATORY EPITHELIUM IN THE AIR RESPIRATION ORGANS OF CLARIAS FUSCUS,CHANNA ASIATICA AND MISGURNUS ANGUILLICAUDATUS

应用扫描电子显微镜与透射电子显微镜技术观察了具气呼吸作用的胡子鲇树枝状鳃上器、月鳢耳片状鳃上器和泥鳅的肠等器官 ,证实 3种淡水鱼类具气呼吸作用的器官表面均被覆一层高度毛细血管化的呼吸上皮。胡子鲇的呼吸上皮表面形态呈玉米棒状 ,月鳢的鳃上器表面为半圆形鹅卵石状 ,泥鳅肠内壁表面如云朵状。这 3种器官的呼吸上皮细胞均为同一种类型 ,是一类特化的扁平上皮细胞 ,兼有哺乳类肺泡Ⅰ型和Ⅱ型上皮细胞的细微结构特征。同时 ,构成气血屏障的三部分即呼吸上皮细胞、毛细血管内皮细胞胞质薄层和两者之间的基底膜与其他脊椎动物的呼吸器官极为相似。

The structure of the air respiratory organs of the fishes,Clarias fuscus with arborescent organs,Channa asiatica with ear-shaped labyrinthine organs and Misgurnus anguillicaudatus with air respiratory intestines has been investigated by scanning and transmission electron microscopy. The resuli suggests that the air respiratory organs are covered by a highly vascularized respiratory epithelium on the surface in all three freshwater species.In C. fuscus,the surface of the respiratory epithelium is corn like. The semicircle cobblestone-shaped protrusions are present on the surface of the labyrinthe organs in C. asiatica. M. anguillicaudatus has a cloud-shaped surface in its inner wall of the intestines. All respiratory epithelial cells of three air respiratory organs are the same type which is a kind of modified squamous epitheial cells. ,They show the ultrastrural characteristics of both type Ⅰ and type Ⅱ epithelial cells of lung alveoli in mammals. At the same time,the blood-air barrier is composed of three layers:the thin layer of the extended cytoplasm of respiratory epithelial cells,the thin sheet of cytoplasm of endothelial cells and the basement membrance between them is similar to that of the respiratory organs in other vertebrates.