大鳞副泥鳅肠道黏液细胞及消化酶活性分布特征研究

采用阿利新兰-碘酸雪夫氏反应(AB-PAS)染色法及酶学方法研究了大鳞副泥鳅成熟个体肠道各段黏液细胞分布及消化酶活性。结果表明, 大鳞副泥鳅肠道黏液细胞分为Ⅰ、Ⅱ、Ⅲ和Ⅳ 4种类型。前肠至后肠, 黏液细胞数量逐渐减少。前肠主要分布Ⅲ和Ⅳ混合型黏液细胞, 后肠则以Ⅱ和Ⅳ型酸性黏液细胞为主。肠道胰蛋白酶活性显著高于淀粉酶和脂肪酶。且后肠消化酶活性显著低于前肠和中肠。根据黏液细胞及消化酶活性分布特点, 表明大鳞副泥鳅属于杂食性鱼类, 前肠为其主要的消化吸收场所, 后肠中性黏液细胞的数量较少以及消化酶活性较低, 表明其对食物的消化吸收功能较弱, 与其为辅助呼吸功能的特点相关。

STUDY ON DISTRIBUTION CHARACTERISTICS OF INTESTINAL MUCOUS CELLS AND DIGESTIVE ENZYME ACTIVITIES IN PARAMISGURNUS DABRYANUS

Distribution of mucous cells and digestive enzyme activities in the intestinal tract of Paramisgurnus dabry-anus were analyzed by AB-PAS histochemical staining and enzymatic testing techniques. The results showed that there were four types of P. dabryanus intestinal tract mucous cells (Ⅰ–Ⅳ). The number of mucous cells decreased from the anterior to posterior intestinal tract. The types of mucous cells in anterior intestinal tract were mainly mixed Ⅲ and Ⅳtypes. The mucous cells, however, consisted of mainly Ⅱ and Ⅳ acidic types in the posterior intestine. Trypsin activity was significantly higher than amylase and lipase activities. Digestive enzyme activities in the posterior intestine were lower than that in the anterior and middle intestine. According to distribution characteristics of the intestinal mucous cells and digestive enzyme activities, P. dabryanus appears to be a type of polyphagic fish. Its intestinal tract has diges-tion and respiratory functions. Digestion and absorption occur in the anterior intestine. In the posterior intestine, the lack of neutral mucus cells and low digestive enzyme activities indicate that its digestive and absorptive abilities are weak. It may be related to its assistive respiratory function.