Fluid and electrolyte transport in the small intestine
Fluid and electrolyte transport in the small intestine
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DOI：
10.1097/00001574-200203000-00004
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发表时间：
2002-03-01
影响因子：
2.5
通讯作者：
Farthing, MJG
中科院分区：
文献类型：
--
作者：
Banks, MR;Farthing, MJG
小肠处于分泌和吸收的动态状态，分泌和吸收的总和导致净吸收。分泌主要是第二信使cAMP、cGMP和钙被激活后，氯化物和碳酸氢盐通过心尖氯化物通道排出的结果。除了囊性纤维化跨膜电导调节外，还发现了其他几个候选氯通道，并被认为在肠道分泌中发挥作用，包括钙依赖的氯通道hCLCA1。利用细胞信使，包括肌醇(3，4，5，6)四烷基二磷酸和磷脂酰肌醇3-激酶，可能通过基侧钾通道起作用，已经描述了导致分泌负控制的途径。离子转运的控制也可以从肠道神经系统的角度来看待。与肠毒素诱导分泌有关的反射神经通路已被证实，并被证明涉及感觉臂上的5-羟色胺、P物质、神经激肽1和2受体，以及分泌运动传出的血管活性肠肽。除了通过Na+/葡萄糖共转运蛋白与钠的主动共转运外，葡萄糖的吸收也被证明是通过载体介导的机制被动发生的，使用膜蛋白葡萄糖转运蛋白2。Curr Coin Gasterenterol 2002，18：176-181(C)2002 Lippincott Williams Wilkins，Inc.
The small intestine is in a dynamic state of secretion and absorption, the sum of which results in net absorption. Secretion is principally the result of chloride and bicarbonate extrusion through apical chloride channels after the activation of the second messengers cAMP, cGMP, and calcium. In addition to the cystic fibrosis transmembrane conductance regulator, several other candidate chloride channels have been identified and proposed to play a role in intestinal secretion, including the calcium-dependent chloride channel hCLCA1. Pathways leading to the negative control of secretion have been described that use cellular messengers, including inositol (3,4,5,6) tetralkisphosphate and phosphatidylinositol 3-kinase, which may act via basolateral potassium channels. The control of ion transport can also be viewed in terms of the enteric nervous system. The reflex neural pathways involved in enterotoxin-induced secretion have been substantiated and shown to involve 5-hydroxytryptamine, substance P, and the neurokinin 1 and 2 receptors in the sensory arm, and vasoactive intestinal peptide in the secretomotor efferents. Absorption of glucose in addition to active cotransport with sodium via the Na+/glucose cotransporter protein has also been shown to occur passively through a carrier-mediated mechanism, using the membrane protein glucose transporter protein 2. Curr Coin Gastroenterol 2002, 18:176-181 (C) 2002 Lippincott Williams Wilkins, Inc.