Ezeasor D N
Anat Anz. 1984;155(1-5):71-83.
The oesophageal epithelium of the rainbow trout, Salmo gairdneri, showed a gradual transition from stratified cuboidal type containing mainly filament-containing cells and globular Type I mucous cells anteriorly to a simple columnar type composed entirely of Type II mucous cells distally. Taste buds were present in the anterior portion; mucous glands were located in the lamina propria in the middle portion and these were replaced with gastric-type glands in the terminal portion. Type I mucous cells severally produced neutral, carboxylated and sulphated mucosubstances while each Type II cell produced all the three types of mucosubstance. In the higher layers of the anterior multilaminar epithelium, the cytoplasm of the filament-containing cells contained numerous small vesicles with cores of flocculent material and the luminal aspects of the surface cells bore microridges. The vesicles contained in Types I and II mucous cells differed in size, arrangement and mode of release. These findings suggest that there is maximal development of protective features, both structural and lubricatory , which aid the oesophagus in the conduction of food materials. Additional sensory and digestive functions are also indicated.
虹鳟鱼（Salmo gairdneri）的食管上皮呈现出一种逐渐过渡的状态，从前端主要包含含丝状细胞和球状I型黏液细胞的复层立方上皮，过渡到远端完全由II型黏液细胞组成的单层柱状上皮。味蕾存在于前部；黏液腺位于中部的固有层，而在末端这些黏液腺被胃型腺体所取代。I型黏液细胞分别产生中性、羧化和硫酸化的黏液物质，而每个II型细胞则产生所有三种类型的黏液物质。在前部复层上皮的较高层中，含丝状细胞的细胞质含有许多带有絮状物质核心的小泡，表面细胞的腔面带有微嵴。I型和II型黏液细胞中的小泡在大小、排列和释放方式上有所不同。这些发现表明，在结构和润滑方面都有最大程度的保护特征发育，这有助于食管传导食物。还显示出额外的感觉和消化功能。
