Mechanisms regulating nutrient induced motor patterns in the isolated small intestine

离体小肠营养诱导运动模式的调节机制

• 批准号: nhmrc : 299807
• 负责人: Prof Joel Bornstein
• 金额: $ 28.52万
• 依托单位国家: 澳大利亚
• 项目类别: NHMRC Project Grants
• 财政年份: 2004
• 资助国家: 澳大利亚
• 起止时间: 2004-01-01 至 2006-12-31
• 项目状态: 已结题
• 来源: https://researchdata.edu.au/mechanisms-regulating-nutrient-small-intestine/82407
• 关键词: Mechanisms; regulating; nutrient; induced; motor

The movements of the small intestine are essential for the digestion and absorption of a meal and consist of two basic patterns during a 3-4 hour period after a meal. These are mixing (or segmentation) and propulsion (or peristalsis). Although it is the subject of ongoing study, much is known about the basic mechanisms that control propulsion, largely because this behaviour is readily seen in isolated segments of gut so it is possible to undertake highly controlled experiments to identify the various cellular components of the system. By contrast, mixing has only been reliably seen in intact animals making studies of the detailed mechanisms responsible for this behaviour much more difficult. What is known is that the composition of a meal controls the relative amount of mixing and propulsion seen at any location along the small intestine. We have recently identified a pattern of contractions in isolated small intestine (duodenum and-or jejunum) that is induced by the presence of a nutrient in the intestine and appears very similar to the mixing behaviour seen in the intact animal. We have shown that this pattern depends on the activity of nerve cells including those that excite the gut muscle and that it depends on the activity of a hormone released from the lining of the gut wall by fats and other nutrients. The aims of this proposal are to identify how nutrients interact to produce this pattern of contractions, the relative roles of specific types of nerve cells and the sites at which the local hormones released by nutrients act. This is important because increasing the proportion of mixing to propulsion enhances the absorption of nutrient from a meal, so if the mechanisms that initiate mixing behaviour can be regulated in a predictable way by specific nutrient, absorption can be enhanced in various malabsorption syndromes.

小肠的运动对食物的消化和吸收是必不可少的，在饭后3-4小时内由两种基本模式组成。它们是混合(或分割)和推进(或蠕动)。尽管这是正在进行的研究的主题，但人们对控制推进的基本机制知之甚少，主要是因为这种行为很容易在肠道的孤立部分看到，因此有可能进行高度受控的实验，以确定系统的各种细胞成分。相比之下，只有在完整的动物身上才能可靠地看到混合，这使得研究导致这种行为的详细机制变得困难得多。已知的是，一顿饭的组成控制着小肠沿线任何位置所看到的混合和推进的相对量。我们最近在分离的小肠(十二指肠和-或空肠)中发现了一种收缩模式，这种模式是由肠道中存在的营养物质引起的，似乎与完整动物的混合行为非常相似。我们已经证明，这种模式依赖于神经细胞的活动，包括那些兴奋肠道肌肉的细胞，它依赖于由脂肪和其他营养物质从肠壁内层释放的激素的活动。这项建议的目的是确定营养物质如何相互作用来产生这种收缩模式，特定类型神经细胞的相对作用，以及由营养物质释放的局部激素的作用部位。这一点很重要，因为增加混合和推进的比例可以增强从食物中吸收营养，所以如果启动混合行为的机制可以通过特定的营养以可预测的方式进行调节，那么各种吸收不良综合征的吸收就可以增强。