禁食对草鱼不同组织、器官蛋白质代谢的影响  

Effects of Starving on Protein Metabolism of Tissues and Organs in the Grass Carp

作　　者：叶元土[1] 蔡春芳[1] 王永玲[1] 丁小峰[1] 蒋蓉[1] 

机构地区：[1]苏州大学生命科学学院,苏州215006

出　　处：《动物学杂志》2006年第3期13-20,共8页Chinese Journal of Zoology

基　　金：苏州大学211工程资助项目(No.Q4114021)

摘　　要：采用肌肉注射、以3H标记的亮氨酸作为示踪氨基酸的大剂量方法、茚三酮测定氨基酸总量的方法,测定了摄食和禁食45 d的草鱼(Ctenopharyngodon idellus)各组织、器官游离氨基酸量、吸收积累的试验氨基酸量、非蛋白质水溶液和蛋白质结合的放射性强度(dpm值)。结果表明,肌肉是草鱼蛋白质代谢最为活跃的组织,禁食使其蛋白质合成量下降了38%左右;脑保持着较高的、稳定的蛋白质代谢活动,其新的蛋白质合成量没有受到禁食的影响;肾脏积累了较多的游离形式的试验氨基酸,禁食并没有使其蛋白质合成量下降,反而有少量增加;肠道是蛋白质代谢活跃的内脏器官,禁食使其蛋白质合成量显著减少,仅为摄食组的30%左右;脾脏进行着较为活跃的蛋白质代谢,禁食45 d后脾脏非蛋白质水溶液和蛋白质结合的dpm值均较摄食组增加了161%,其新合成的蛋白质量为摄食条件下的2.6倍;禁食并没有使肝胰脏蛋白质合成量受到影响;心脏也进行着较为活跃的蛋白质代谢,禁食使其新的蛋白质合成量降低了一半左右。通过氨氮排泄率和排泄氨氮占体蛋白质氮百分比的分析结果,草鱼在禁食过程中整体蛋白质代谢活动在5 d以前快速下降,氨氮排泄率从第3 d的404.44μmol(N)/kg.h下降到第5 d的325.68μmol(N)/kg.h,5 d以后氨氮排泄率趋于稳定(水温在21.5℃),此时草鱼的氨氮排泄率为4.56 mg/kg.h、氨氮排泄的氮占鱼体蛋白质的百分比为0.37%,可以作为草鱼内源性氨氮的排泄参考值。The quantity of free amino acids in the organs and tissues of Grass Carp （ Ctenopharyngodon idellus ） starving or feeding for 45 days was measured by the ninhydrin colorimetric analysis method. The specific radioactivity of the L-[4,5-^3 H] leucine was measured by the large-dose method and the active protein metabolism was measured by the muscle injection method as well. The muscle is the most active tissue for the protein metabolism, and starvation made the synthesized protein quantity decrease about 38 %. The brain maintains high and stable protein metabolism, and its new synthesized protein quantity is not affected by starvation. Free amino acids are accumulated in the kidney and the synthesized protein quantity is increased in kidney after starvation. The protein synthesis is very active in intestine. However,the synthesized protein quantity in the intestine after starvation is only 30 percent of the feeding fish. The protein metabolism accelerates in spleen after starvation for 45 days, and the synthesized protein quantity is 2.6 times of feeding fish. The synthesized protein quantity in the intestine is decreased for 50% after starvation for 45 days. The excretion ratio of the ammonia nitrogen was measured during starvation.The ratio is decreased from 404.44 μmol（N）/kg·h to 100.44 μmol（N）/kg·h with the starvation from 3 days to 45 days. The ratio of the excretion ammonia nitrogen to the protein nitrogen of the body was calculated based on the changes in the chemical content during the starvation.The ratio is greatly decreased within 5 days of starvation,from 0.64% to 0.37% .The ratio is decreased from 0.37 % to 0.28 % from 5 days to 45 days of starvation.

关 键 词：蛋白质 氨基酸 氨氮 草鱼 

分 类 号：Q591.1[生物学—生物化学]