Digestion of a single meal affects gene expression of ion and ammonia transporters and glutamine synthetase activity in the gastrointestinal tract of freshwater rainbow trout
Digestion of a single meal affects gene expression of ion and ammonia transporters and glutamine synthetase activity in the gastrointestinal tract of freshwater rainbow trout
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DOI：
10.1007/s00360-011-0622-y
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发表时间：
2012-04-01
影响因子：
2
通讯作者：
Wood, Chris M.
中科院分区：
文献类型：
--
作者：
Bucking, Carol;Wood, Chris M.
对淡水虹鳟鱼（Oncorhynchus mykiss）的实验表明，在禁食1周后，消化如何影响胃肠道转运蛋白的转录表达。定量实时聚合酶链反应，以测量相对mRNA表达的三个先前克隆和测序转运蛋白[H+-K+-ATP酶（HKA），Na+/HCO 3-协同转运蛋白（NBC），和恒河猴糖蛋白（Rhbg 1;氨转运蛋白）]在24小时的时间过程后喂养。血浆总氨从饲喂前水平增加约3倍至288 μ mol l（-1），而食糜上清液中的总氨水平达到比血浆水平高6倍（1.8 mmol l（-1））。喂食似乎对胃HKA或Rhbg 1的相对mRNA表达没有统计学显著影响。然而，胃NBC的相对mRNA表达增加24小时后摄入的一餐。沿着肠道，摄食增加了Rhbg 1的相对mRNA表达，但对NBC的表达没有影响。胃HKA的表达是在肠道的淡水虹鳟鱼检测不到。消化增加谷氨酰胺合成酶的活性在后肠在12和24小时后喂养。这项研究是第一次表明，有消化相关的基因表达和酶活性的硬骨鱼胃肠道的变化，说明这个器官的动态可塑性。这些餐后变化发生在消化一顿饭的相对较短的时间内。
Experiments on freshwater rainbow trout, Oncorhynchus mykiss, demonstrated how digestion affected the transcriptional expression of gastrointestinal transporters following a single satiating meal (similar to 3% body mass ration) after a 1-week fast. Quantitative real-time polymerase chain reaction was employed to measure the relative mRNA expression of three previously cloned and sequenced transporters [H+-K+-ATPase (HKA), Na+/HCO3- cotransporter (NBC), and the Rhesus glycoprotein (Rhbg1; an ammonia transporter)] over a 24-h time course following feeding. Plasma total ammonia increased about threefold from pre-feeding levels to 288 mu mol l(-1), whereas total ammonia levels in chyme supernatant reached a sixfold higher value (1.8 mmol l(-1)) than plasma levels. Feeding did not appear to have a statistically significant effect on the relative mRNA expression of the gastric HKA or Rhbg1. However, the relative mRNA expression of gastric NBC was increased 24 h following the ingestion of a meal. Along the intestinal tract, feeding increased the relative mRNA expression of Rhbg1, but had no effect on the expression of NBC. Expression of the gastric HKA was undetectable in the intestinal tract of freshwater rainbow trout. Digestion increased the activity of glutamine synthetase in the posterior intestine at 12 and 24 h following feeding. This study is among the first to show that there are digestion-associated changes in gene expression and enzyme activity in the gastrointestinal tract of teleost fish illustrating the dynamic plasticity of this organ. These postprandial changes occur over the relative short-term duration of digesting a single meal.