格林在中央调节养中的作用
M Nakazato1, N Murakami, Y Date
1Third Department of Internal Medicine, Miyazaki Medical College, Kiyotake, Japan. nakazato@post.miyazaki-med.ac.jp
Nature
|February 24, 2001
概括
格林是一种类激素,通过作用于下丘脑,刺激食并增加体重. 这项研究揭示了 ghrelin 的存在.
科学领域:
- 神经内分泌学神经内分泌学
- 代谢调节 代谢调节 代谢调节
- 生理学 生理学 生理学
背景情况:
- 格雷林是一种已知的刺激生长激素释放的乙烯酸激素.
- 产生格林的神经元位于下丘脑,整个大脑都有受体,这表明它们的中心作用.
- 格林的精确生理功能,特别是能量恒温,仍然需要完全定义.
研究的目的:
- 为了研究格林在下丘脑能量恒温的调节中的作用.
- 为了确定格林是否影响食行为和体重增加.
- 阐明神经元通路和相互作用涉及格林对养的影响.
主要方法:
- 在大鼠的脑内内注射格林.
- 对抗格雷林的免疫球蛋白G的使用.
- 在特定的下丘脑核 (NPY和AGRP神经元) 中对Fos蛋白表达的分析.
- 使用NPY和AGRP抗体和对抗剂.
- 评估格林对NPY基因表达和瘦素诱导的食减少的影响.
主要成果:
- 在大鼠中,脑内内格林的使用显著刺激了食和增加了体重.
- 格雷林甚至在生长激素缺乏的老鼠中增加了食.
- 抗ghrelin 免疫球蛋白 G 抑制的养.
- 格林激活了关键养调节区域的神经元,包括神经Y (NPY) 和agouti相关蛋白 (AGRP) 神经元.
- 抑制NPY和AGRP阻断了 ghrelin诱导的食.
- 格雷林增强了NPY基因表达,并抵消了勒的抑制食欲的作用,表明了竞争性相互作用.
结论:
- 格林林作为食行为的生理调解者.
- 格林在下丘脑能量恒温的调节中起着重要作用.
- 格雷林可能通过刺激养和生长激素释放来促进生长调节.
相关概念视频
Neural Regulation
Digestion begins with a cephalic phase that prepares the digestive system to receive food. When our brain processes visual or olfactory information about food, it triggers impulses in the cranial nerves innervating the salivary glands and stomach to prepare for food.
Hormonal Regulation
Hormones regulate a significant portion of digestion through activation of the neuroendocrine system. The neuroendocrine system of digestion contains many different hormones all with multiple functions that are both, directly and indirectly, involved in digestion.
Hormonal Regulation
The renin-aldosterone system is an endocrine system which guides the renal absorption of water and electrolytes, thus managing blood pressure and osmoregulation. Activation of the system begins in the kidneys with a small cluster of cells adjacent to the afferent and efferent blood vessels of the renal corpuscle. As the nephrons are filtering blood, juxtaglomerular cells monitor blood pressure. If they detect a decrease in pressure, they release the hormone renin into the bloodstream.
GPCRs Regulate Adenylyl Cylase Activity
Some GPCRs transmit signals through adenylyl cyclase (AC), a transmembrane enzyme. AC helps synthesize second messenger cyclic adenosine monophosphate (cAMP). AC catalyzes cyclization reaction and converts ATP to cAMP by releasing a pyrophosphate. The pyrophosphate is further hydrolyzed to phosphate by the enzyme pyrophosphatase, which drives cAMP synthesis to completion. However, cAMP is rapidly degraded to 5′ AMP by the enzymes phosphodiesterase (PDE), preventing overstimulation of cells.
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Digestive activity regulation hinges on three primary components. Activation is prompted by a multitude of mechanical and chemical indicators, primarily detected by receptors within the stomach and intestines' walls. These receptors predominantly respond to factors such as mechanical stretching of the organ walls, changes in pH and osmolarity, and the presence of digesting materials and their by-products.
The effectors in this regulation system are glands and smooth muscles. Activation of these...
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Regulation of Food Intake
Short-term regulation of food intake primarily involves neural signals from the gastrointestinal (GI) tract, blood nutrient levels, and GI tract hormones. Communication between the gut and brain via vagal nerve fibers plays a significant role in evaluating the contents of the gut. Clinical studies have shown that protein ingestion produces a more prolonged response in these nerve fibers compared to an equivalent amount of glucose. Additionally, the activation of stretch receptors caused by GI...


