牙鲆幼鱼消化道内蛋白酶活性及食糜蛋白的GFP示踪

Protease activity and chyme protein tracing by GFP in the digestive tract of flounder Paralichthys olivaceus

中文关键词: 牙鲆  消化道  绿色荧光蛋白  示踪  蛋白酶活力

英文关键词: Paralichthys olivaceus  Digestive tract  Trace  GFP  Protease activity

中文摘要:

      用添加绿色荧光蛋白(GFP)饲料投喂牙鲆，研究了不同消化时间内食糜在牙鲆消化道中的分布情况，采用福林 酚法测定了不同时间胃、前肠、中肠和后肠各组织黏液蛋白酶活性。结果表明，牙鲆在摄食后消化道蛋白酶活性随着食糜在消化道内的分布而变化，食物的刺激引起消化腺体分泌蛋白酶。牙鲆摄食后1 h食糜达到中肠，胃和中肠蛋白酶活性与空腹相比迅速增高；食糜在5 h时遍布整个消化道，此时胃蛋白酶活性几乎检测不出，而前肠蛋白酶活性迅速增高，5 h达到最高，然后开始降低；8 h时中肠蛋白酶活性一直很高，之后降低；而后肠直到12 h其蛋白酶活性仍维持在较高水平，说明牙鲆这种消化道较短的鱼类其肠道比胃在蛋白质消化过程中发挥更重要的作用。

英文摘要:

      The distribution of the chyme in the digestive tract of flounder Paralichthys olivaceus was studied by adding green fluorescent protein (GFP) to the bait. The protease activity in the mucus of different part of the digestive tract was studied by the Folin-phenol reagent method post ingestion. The results showed that the protease activity changed with chyme distribution in the digestive tract after feedion. The chyme reached the midgut 1 h after ingestion, and the protease activity of stomach and midgut increased rapidly. The chyme was distributed in the whole digestive tract 5 h after ingestion, and the stomachic protease activity reduced to near null.The protease activity in the midgut kept at the highest level until 8 h.The protease activity in the hindgut kept at the high level until 12 h after feeding. The results showed that the intestines might be more significant in protein digestion than the stomach for the fish with short digestive tract. 