The pepsin and trypsin activities and some of the properties of the two enzymes of southern sheatfish larvae were studied. The results were as follows: the highest level of trypsin activity is in the foregut in all...The pepsin and trypsin activities and some of the properties of the two enzymes of southern sheatfish larvae were studied. The results were as follows: the highest level of trypsin activity is in the foregut in all measured tissues; from foregut to hindgut, trypsin activities decrease; the pH optimum of trypsin activity is pH9.0; the strongest pepsin activity is in the stomach; the proper density of haemoglobin for detecting pepsin activity is 1.0%. These data are useful in solving applied nutritional problems, such as the adequacy of artificial food to the digestive abilities of the fish.展开更多
The present study was conducted to determine the change of digestive physiology in sea cucumber Apostichopus japonicus(Selenka) induced by corn kernels meal and soybean meal in diets. Four experimental diets were test...The present study was conducted to determine the change of digestive physiology in sea cucumber Apostichopus japonicus(Selenka) induced by corn kernels meal and soybean meal in diets. Four experimental diets were tested, in which Sargassum thunbergii was proportionally replaced by the mixture of corn kernels meal and soybean meal. The growth performance, body composition and intestinal digestive enzyme activities in A. japonicus fed these 4 diets were examined. Results showed that the sea cucumber exhibited the maximum growth rate when 20% of S. thunbergii in the diet was replaced by corn kernels meal and soybean meal, while 40% of S. thunbergii in the diet can be replaced by the mixture of corn kernels meal and soybean meal without adversely affecting growth performance of A. japonicus. The activities of intestinal trypsin and amylase in A. japonicus can be significantly altered by corn kernels meal and soybean meal in diets. Trypsin activity in the intestine of A. japonicus significantly increased in the treatment groups compared to the control, suggesting that the supplement of corn kernels meal and soybean meal in the diets might increase the intestinal trypsin activity of A. japonicus. However, amylase activity in the intestine of A. japonicus remarkably decreased with the increasing replacement level of S. thunbergii by the mixture of corn kernels meal and soybean meal, suggesting that supplement of corn kernels meal and soybean meal in the diets might decrease the intestinal amylase activity of A. japonicus.展开更多
文摘The pepsin and trypsin activities and some of the properties of the two enzymes of southern sheatfish larvae were studied. The results were as follows: the highest level of trypsin activity is in the foregut in all measured tissues; from foregut to hindgut, trypsin activities decrease; the pH optimum of trypsin activity is pH9.0; the strongest pepsin activity is in the stomach; the proper density of haemoglobin for detecting pepsin activity is 1.0%. These data are useful in solving applied nutritional problems, such as the adequacy of artificial food to the digestive abilities of the fish.
基金funded by the National Natural Science Foundation of China (Nos.31172426 and 31372549)the Ministry of Science and Technology of China (No.2011BAD13B03)
文摘The present study was conducted to determine the change of digestive physiology in sea cucumber Apostichopus japonicus(Selenka) induced by corn kernels meal and soybean meal in diets. Four experimental diets were tested, in which Sargassum thunbergii was proportionally replaced by the mixture of corn kernels meal and soybean meal. The growth performance, body composition and intestinal digestive enzyme activities in A. japonicus fed these 4 diets were examined. Results showed that the sea cucumber exhibited the maximum growth rate when 20% of S. thunbergii in the diet was replaced by corn kernels meal and soybean meal, while 40% of S. thunbergii in the diet can be replaced by the mixture of corn kernels meal and soybean meal without adversely affecting growth performance of A. japonicus. The activities of intestinal trypsin and amylase in A. japonicus can be significantly altered by corn kernels meal and soybean meal in diets. Trypsin activity in the intestine of A. japonicus significantly increased in the treatment groups compared to the control, suggesting that the supplement of corn kernels meal and soybean meal in the diets might increase the intestinal trypsin activity of A. japonicus. However, amylase activity in the intestine of A. japonicus remarkably decreased with the increasing replacement level of S. thunbergii by the mixture of corn kernels meal and soybean meal, suggesting that supplement of corn kernels meal and soybean meal in the diets might decrease the intestinal amylase activity of A. japonicus.
文摘目的探讨长期甲醛固定的大鼠视网膜胰蛋白酶消化的最佳消化时间和最佳胰蛋白酶浓度。方法健康♂ SD大鼠，颈椎脱臼处死，摘取眼球，放入4％甲醛固定液，固定时间为2 d、2周、4周、3月、5月、7月。分离固定不同时间的视网膜，放入3％、6％、9％胰蛋白酶消化，37℃恒温箱孵育。分别记录固定不同时间的视网膜在3％、6％、9％胰蛋白酶中消化完全所需时间。铺片操作，行 PAS 染色。显微镜下记录视网膜消化情况。结果新鲜眼球常规固定48 h，3％胰蛋白酶37℃消化3.5 h，视网膜消化完全。对于甲醛固定2周及1月的大鼠眼球，采用常规胰蛋白酶浓度（3％），仅延长胰蛋白酶的消化时间至9 h 及14 h，可以达到常规固定组织的消化效果。对于固定3月的大鼠眼球，采用常规浓度的胰蛋白酶仅延长消化时间至22 h，同样可以得到完整的视网膜血管铺片，且提高胰蛋白酶浓度对于缩短视网膜消化时间的影响不大。而对于固定5～7月的大鼠眼球，6％和9％浓度的胰蛋白酶可以在一定程度上缩短视网膜消化的时间至22 h 和28 h，有利于得到相对完整的视网膜血管。结论固定时间短于3月的眼球组织，采用3％胰蛋白酶消化，延长消化时间可达到最佳消化效果。对于固定5～7月的视网膜组织，不仅需要延长消化时间，还需要通过提高胰蛋白酶浓度至6％，才可以获得最佳消化效果的视网膜血管。
