野生与养殖哲罗鱼消化系统及消化酶的比较研究

Comparative study on the digestive system and digestive enzymes of wild and cultivated Hucho taimen

采用组织学方法对野生与养殖哲罗鱼(Hucho taimen Pallas)消化系统的形态及组织结构进行比较研究,采用聚丙烯酰胺凝胶电泳方法比较了两个群体哲罗鱼3种消化酶的相对含量。结果表明,野生与养殖哲罗鱼的消化系统在形态上存在一定差异,在组织结构上无明显差异。两个群体哲罗鱼在食道与胃酯酶相对含量上差异不显著(P>0.05),在肝脏与幽门盲囊酯酶相对含量上差异显著(P<0.05),在肠道酯酶的相对含量上差异极为显著(P<0.01)。两个群体哲罗鱼在食道与胃淀粉酶的相对含量上差异不显著(P>0.05),在肝脏与肠道淀粉酶的相对含量上差异显著(P<0.05),在幽门盲囊淀粉酶的相对含量上差异极为显著(P<0.01)。哲罗鱼的蛋白酶表达存在一定的pH依赖性,在体外酸性条件下(pH3),两个群体哲罗鱼只有食道与胃有蛋白酶表达;在体外碱性条件下(pH9),两个群体哲罗鱼只有幽门盲囊与肠道有蛋白酶表达;两种pH条件下,两个群体哲罗鱼各组织中蛋白酶的相对含量差异均不显著(P>0.05)。两个群体哲罗鱼的消化系统结构及消化酶含量所表现出的差异与其生活环境及食物有关。

The morphology and histology of the digestive system of wild and cultivated Hucho taimen has been studied using histological method.The results showed that there were some differences between the wild and cultivated types in the shape of digestive system, but the differences in histology of esophagus, stomach, liver, pyloric caecum and intestine were not clear. The digestive enzymes of the two populations were studied by means of polyacrylamide gel electrophoresis. The results showed that differences of relative esterase content in esophagus and stomach between the two populations were not significant （P〉0.05）, while in liver and pyloric caecum the differences were significant （P〈0.05）. In intestine, the relative enzyme content were extremely significant （P〈0.01）. The difference of relative amylase content in esophagus and stomach between the two populations is not significant （P〉0.05）, in liver and intestine, the difference was significant （P〈0.05）, in pyloric caecum, the difference was extremely significant （P〈0.01） .The expression of proteases relied on pH value. Only in esophagus and stomach there was protease＇ s expression of the .two populations in acidic condition （pH=3）. In alkaline condition （pH=9）, pyloric caecum and intestine had the expression of proteases. In both conditions, the difference relative protease content of each tissue between the two populations was not prominent （P〉0.05）. It could bc concluded that difference of digestive system and digestive enzymes between the two populations relied on their living condition and food. [Journal of Fishery Sciences of China, 2008, 15 （2） ： 330-336]