厚颌鲂仔稚鱼消化酶活性变化研究

Assessment of digestive enzymes activities during larval development of Megalobrama pellegrini

测定了厚颌鲂(Megalobrama pellegrini)仔稚鱼从出膜到30日龄的生长、可溶性蛋白含量及消化酶活性。结果表明:初孵仔鱼即能检测到胰蛋白酶、淀粉酶、脂肪酶活性,2日龄检测到碱性磷酸酶活性。投喂组可溶性蛋白含量随日龄的增加显著增加(P<0.05),饥饿组可溶性蛋白含量6日龄前增加不显著,6日龄后开始下降。所测消化酶的全活力与比活力呈现出不同的变化模式。各消化酶的全活力基本是随日龄的增加而增加。投喂组胰蛋白酶比活力在10日龄达最大值,随后显著下降;饥饿组胰蛋白酶比活力在4日龄达最大值,随后显著下降。投喂组淀粉酶在5日龄达到最大值,从6日龄到12日龄维持在一个较低水平,随后增加至15日龄的(0.912±0.090)mU/mg,在试验后期均维持在一个相对较低的水平;饥饿组淀粉酶比活力的最大值出现在1日龄,从2日龄到8日龄变化不显著,8日龄后显著下降。投喂组脂肪酶比活力在18日龄达最大值,随后显著下降;饥饿组脂肪酶比活力1日龄到6日龄变化不显著,6日龄后显著下降。投喂组碱性磷酸酶比活力从2日龄到12日龄显著上升,12日龄达到最大值,随后显著下降;饥饿组碱性磷酸酶比活力从2日龄到8日龄显著上升,8日龄达到最大值,随后显著下降。

Growth, soluble protein content and the activities of some digestive enzymes were studied in Megalobroma pelle- grini larvae during the first month of life. The results of experiment were as follows ： On the first day, the activities of tryp- sin, amylase and lipase were detected. The activities of alkaline phosphatase were detected on the 2 nd day. Soluble protein content of the experimental group increased significantly with age （ P 〈 O. 05 ）. Soluble protein content of the starvation group had no obvious change from day 1 to day 6, and then decreased. The variation model was different between total ac- tivities and specific activities. The total activities of digestive enzymes increased with age. The trypsin specific activities of the experimental group reached the maximum on the 10 th day, then decreased sharply. The trypsin specific activities of the starvation group reached the maximum on the 4 day, then decreased sharply. On the 5 th day, the amylase specific activi- ties reached the maximum, and then decreased to a low level, and maintained from day 6 to day 12. The specific activities increased to the peak of （0. 912 ＋0. 09） m U/mg on the 15 th day, and then decreased to a very low level from day 15 to day 30. The amylase specific activities of the starvation group reached the maximum on the 1 st day. From day 2 to day 8, the amylase specific activities had no obvious change, and then decreased sharply. The lipase specific activities of the ex- perimental group reached the maximum on the 18 th day. After day 18, the activities decreased sharply with age. The lipase specific activities of the starvation group had no obvious change from day 1 to day 6, and then decreased sharply. The AKP specific activities of the experimental group increased sharply from day 2 to day 12. On the 12 th day, the specific activities reached the maximum, then decreased sharply from day 12 to day 30. The AKP specific activities of the starvation group in- creased sharply from day 2 to day 8, and then decreased sharply.