皱纹盘鲍食道的结构与功能

The structure and function of the esophagus of disk abalone Haliotis discus hannai

以组织学、组织化学、扫描电镜和透射电镜观察及酶活性测定等方法研究了皱纹盘鲍的食道。食道可分为前、中、后三段 ,中段又可分为食物通道和食道侧囊。食道粘膜上皮由纤毛柱状细胞、粘液细胞、颗粒状腺细胞、微绒毛细胞和分泌细胞组成。纤毛柱状细胞参与运输食物和分泌物 ,并呈现吸收细胞的结构特征 ;粘液细胞分泌中性和酸性粘多糖 ;颗粒状腺细胞内充盈分泌颗粒 ;微绒毛细胞呈现吸收细胞的特征 ;分泌细胞具很强的蛋白酶等酶活性 ,能以顶浆分泌形式分泌消化酶 ,该细胞还具有吸收和细胞内消化作用。

The esophagus of disk abalone, Haliotis discus hannai Ino, was studied with histological and histochemical methods, scanning and transmission electron microscopic observation, and tests for some enzymatic activity. The esophagus is divided into anterior, mid and posterior partitions. The mid esophagus is again divisible into two structurally and functionally distinct regions, a central food channel and two lateral pouches. The epithelium of the esophagus consists of five types of cells, ciliated columnar cell, mucous cell, granular gland cell, cell with microvilli and secretory cell. Ciliated columnar cells participate mainly in transport of food and secretion, and show structural features of absorptive cells. Mucous cells secrete neutral and acid mucopolysaccharide. Granular gland cells contain a large number of secretory granules. Cells with microvilli also show the features of absorptive cells. Secretory cells, the main glandular cells in the lateral pouches, show strong activity of proteinase and non specific esterase. They may secrete digestive enzymes by the apocrine. The secretory cells may also participate in absorption and intracellular digestion of food. The epithelium of the mid esophagus shows activity of three plant polysaccharide enzymes by tests in vitro.