Ghrelin与肝脏疾病关系的研究进展

Ghrelin是1999年首次发现的一种包含28个氨基酸的脑肠肽,为生长激素促分泌素受体的内源性配体,具有促进生长激素释放、增加进食、促进胃酸分泌、调节胃肠道运动、调节血糖、肝脏保护等多种功能。越来越多的研究发现,Ghrelin水平在肝脏疾病中发生改变,Ghrelin可能通过改善炎症反应、降低氧化应激及细胞凋亡、抗纤维化等多种途径发挥肝脏保护作用。Ghrelin与肝脏疾病的关系备受关注。     

Ghrelin及其受体在肿瘤发生中的作用

Ghrelin是1999年发现的首个生长激素促泌物受体的内源性配体,具有广泛的生物学效应。包括促进生长激素分泌,增进食欲,维持能量代谢正平衡,调节心血管和免疫系统功能等。目前Ghrelin和肿瘤疾病之间相互关系受到了广泛重视,已经积累了许多的研究成果,表明Ghrelin及其受体参与了多种肿瘤的发病机理和相关病理生理改变。     

Ghrelin与消化系统的关系研究进展

Ghrelin是新近发现的一种脑肠肽,1999年由日本科学家Kojima从大鼠胃中分离出来,是生长激素促分泌素受体(GHSR)的天然配体,故又称生长素。Ghrelin可调节生长激素(GH)和其他激素的释放,调节能量代谢,抑制肿瘤细胞增殖,影响心血管功能。近来研究发现,Ghrelin与胃动素(motilin)及消化系统关系密切,此文就这方面的研究进展作一综述。     

Ghrelin与动脉粥样硬化

Ghrelin是近年来发现的一种促进生长激素分泌的多肽,是生长激素促分泌物受体的内源性配体。研究发现,ghrelin除了具有增加摄食及调节能量代谢的作用外,还具有降低血压、对抗炎症反应、保护血管内皮细胞等多种生物学效应,提示其在心血管疾病尤其是在动脉粥样硬化方面具有潜在的治疗效应。     

Ghrelin与骨质疏松相关性的研究进展

Ghrelin属于脑肠肽,是生长激素促分泌素受体的内源性配体,具有与生长激素相关的多种生物学效应。早期研究认为,神经性厌食症和胃切除术所致继发性骨量减低主要与多种维生素和矿物质吸收不良有关。现在认为,胃内泌酸腺分泌的Ghrelin可能是介导继发性骨质疏松的候选激素。多数临床研究支持Ghrelin与骨量、骨密度正相关,Ghrelin在体外促进成骨细胞增生、分化及矿化。但Ghrelin在体外抑制骨髓间充质干细胞向成骨细胞分化,促进其成脂分化。在神经性厌食症继发骨质疏松患者中,Ghrelin反常升高可引起生长激素抵抗和促肾上腺皮质激素升高,进而导致全身性骨流失以及青少年峰值骨量获得性缺失。     

Ghrelin与生长激素关系的研究进展

Ghrelin是最近发现的一种脑—肠肽,具有强烈的促生长激素(GH)释放的作用,此外还能调节能量代谢、食欲、睡眠等。目前认为,ghrelin可同时作用于人体腺垂体和下丘脑,与促生长激素释放激素协同促进GH分泌。Ghrelin的分泌具有性别差异,可被生长抑素抑制,但外周GH水平对ghrelin的分泌无明显影响。另外,胰岛素样生长因子1可通过下调ghrelin受体的表达而影响其作用。     

Ghrelin与消化系统疾病的研究进展

Ghrelin是一个由28个氨基酸组成的脑肠肽,是在1999年由Kojima等[1]发现的生长素促分泌激素受体的内源性配体,与其受体结合后可产生广泛的生物学效应,具有促生长激素分泌作用的同时,具有增强食欲,减少脂肪利用,增加体重,维持能量正平衡的调节能量代谢的作用。另外,Ghrelin还控制胃动力,促进胃酸分泌,调节胰腺的内外分泌功能,影响血糖水平。Ghrelin与胃肠道类腺癌有关。最近研究发现,它的拮抗剂能减慢结肠传输时间。现将Ghrelin与消化系统相关疾病的研究进展综述如下。1概述1.1Ghrelin的分子结构Ghrelin是由28个氨基酸组成的小分子多肽,人…     

Ghrelin与生长激素关系的研究进展

Ghrelin是最近发现的一种脑-肠肽,具有强烈的促生长激素（GH）释放的作用,此外还能调节能量代谢、食欲、睡眠等.目前认为,ghrelin可同时作用于人体腺垂体和下丘脑,与促生长激素释放激素协同促进GH分泌.Ghrelin的分泌具有性别差异,可被生长抑素抑制,但外周GH水平对ghrelin的分泌无明显影响.另外,胰岛素样生长因子1可通过下调ghrelin受体的表达而影响其作用.     

Ghrelin,一个促生长激素分泌及调节能量代谢的新多肽

Ghrelin是一个由 2 8个氨基酸组成的多肽 ,3位丝氨酸上有酰化基团。它是第一个被发现的生长激素促分泌剂受体 (GHS R)的内源性配体。Ghrelin主要由胃分泌 ,下丘脑、肾脏、胎盘均有分泌。GHS R分布在多种组织 ,而且有不同的亚型 ,它有很强的促生长激素 (GH)释放的作用 ,可使循环中GH迅速、显著而持久地增加 ,甚至比生长激素释放激素的作用还强。Ghrelin是促进食欲的脑肠肽 ,参与下丘脑、垂体和胃肠道共同对能量平衡的调节     

Ghrelin与肥胖、胰岛素抵抗和2型糖尿病的研究进展

Ghrelin是由胃底细胞分泌的小分子活性肽,是生长激素促泌物受体的内源性配体,具有促进生长激素分泌、促进摄食、参与能量代谢等多种作用。研究表明,Ghrelin与多种外周信号共同参与调节机体的糖脂代谢。IR是T2DM发生发展的重要病理生理基础,而肥胖是IR和T2DM的共同危险因素。Ghrelin与肥胖和T2DM之间有着密切而复杂的关系。针对Ghrelin的深入研究有望为肥胖和T2DM诊断和治疗开辟一条新途径。     

Ghrelin and cancer

Ghrelin is a peptide hormone that was originally isolated from the stomach as the endogenous ligand for the growth hormone secretagogue receptor (GHSR). Ghrelin has many functions, including the regulation of appetite and gut motility, growth hormone release from the anterior pituitary and roles in the cardiovascular and immune systems. Ghrelin and its receptor are expressed in a number of cancers and cancer cell lines and may play a role in processes associated with cancer progression, including cell proliferation, apoptosis, and cell invasion and migration.     

Endocrine and metabolic activities of a recently isolated peptide hormone ghrelin, an endogenous ligand of the growth hormone secretagogue receptor

Ghrelin is a member of the group of growth hormone secretagogues (GHSs). It is a peptide hormone, recently isolated from stomach as an endogenous ligand for the growth hormone secretagogue receptor (GHS-R). Ghrelin is mostly produced by the stomach, although its production has been proved in various tissues. It is a potent releaser of growth hormone (GH) from anterior pituitary cells, but it also stimulates the release of other hypophyseal hormones. Ghrelin stimulates food intake and induces metabolic changes leading to an increase in body weight and body fat mass. This effect seems to be independent of GH action and needs an intact NPY/AGRP (neuropeptide Y/agouti-related protein) system. Plasma ghrelin levels are decreased in obesity, elevated in cachexia and show a diurnal rhythm. Its preprandial elevation suggests, that it might be a signal for meal initiation. Ghrelin further stimulates the release of gastric acid and gastric motility and affects pancreatic functions. It has vasodilatatory, cardioprotective and antiproliferative effects. This article is focused on ghrelin's endocrine and metabolic functions.     

Ghrelin与能量平衡及糖代谢的关系

Ghrelin是生长激素促分泌物受体的第一个内源性配体,具有促进生长激素分泌、促进摄食、减少脂肪利用等作用,并与胰岛素、瘦素等相互作用,影响能量平衡及糖代谢,因而与肥胖、胰岛素抵抗及2型糖尿病密切相关。进一步研究ghrelin的作用对研究肥胖、胰岛素抵抗、2型糖尿病的发生、发展过程具有指导意义。     

胃促生长素与消化道运动

胃促生长素(ghrelin)是新发现的内源性多肽,有促生长激素分泌和调节食欲、调节能量代谢的作用,它主要由胃底X/A样细胞分泌,广泛分布于胃和肠道组织,且与胃动素在结构上有高度相同性,故其与消化道运动的关系近来备受关注,现综合有关文献,对ghrelin与消化道运动的关系作一综述.     

Ghrelin enhances the proliferating effect of thyroid stimulating hormone in FRTL-5 thyroid cells

Ghrelin regulates cell proliferation through the growth hormone secretagogue receptor (GHS-R). We confirmed the expression of GHS-R in FRTL-5 thyroid cells and investigated the effects of ghrelin in thyrocytes using FRTL-5 cells. Ghrelin increased intracellular calcium levels but not intracellular cyclic AMP levels. Ghrelin activated Erk within 2min, then activated Akt and STAT3. Erk phosphorylation was inhibited by the calcium inhibitor cyclopiazonic acid (CPA). Ghrelin alone did not stimulate FRTL-5 cell proliferation but enhanced the effects of thyroid stimulating hormone (TSH). Pretreatment with TSH potentiates the growth effects of ghrelin in thyroid cells, and p66Shc, a growth factor receptor adaptor protein, might mediate these synergistic effects. Ghrelin phosphorylated TSH-induced p66Shc, which was inhibited by CPA. Ghrelin did not affect the proliferation of ARO cells, which showed no increased expression of p66Shc after TSH treatment. Thus, ghrelin-induced intracellular calcium signaling enhanced the TSH-induced proliferation of thyrocytes, possibly mediated by the p66Shc pathway.     

Ghrelin的胃肠动力学研究进展

Ghrelin是1999年被发现的生长激素促分泌激素受体的内源性配体,是胃动素相关类家族的调节肽。Ghrelin主要由胃基底部泌酸腺X/A样细胞分泌,并释放进入血液循环。它除了可以刺激生长激素、泌乳刺激素及促肾上腺皮质激素释放外,还可以促进食欲、增强胃肠动力、刺激胃酸分泌、影响睡眠节律、调节胰腺内分泌功能、调节糖代谢、能量代谢等。此文综述了Ghrelin在胃肠动力方面的研究进展。     

Ghrelin与阻塞性睡眠呼吸暂停低通气综合征并代谢综合征

Ghrelin是迄今发现的体内唯一的生长激素促分泌物质受体的内源性配体,它不仅是生长激素的强烈促分泌剂,还促进摄食,对调节能量代谢也有重要作用,并可能参与肥胖和2型糖尿病的发病过程,在体内还可以促进机体慢波睡眠,在阻塞性睡眠呼吸暂停低通气综合征（obstructive sleep apnea-hyponea syndrome,OSAHS）患者中尤其明显。本文主要阐述Ghrelin的一般特点及其与OSAHS及代谢综合征的关系。     

Ghrelin's second life: from appetite stimulator to glucose regulator

Ghrelin, a 28 amino acid peptide hormone produced by the stomach, was the first orexigenic hormone to be discovered from the periphery. The octanoyl modification at Ser3, mediated by ghrelin O-acyltransferase (GOAT), is essential for ghrelin's biological activity. Ghrelin stimulates food intake through binding to its receptor (GRLN-R) on neurons in the arcuate nucleus of the hypothalamus. Ghrelin is widely expressed throughout the body; accordingly, it is implicated in several other physiological functions, which include growth hormone release, gastric emptying, and body weight regulation. Ghrelin and GRLN-R expression are also found in the pancreas, suggesting a local physiological role. Accordingly, several recent studies now point towards an important role for ghrelin and its receptor in the regulation of blood glucose homeostasis, which is the main focus of this review. Several mechanisms of this regulation by ghrelin have been proposed, and one possibility is through the regulation of insulin secretion. Despite some controversy, most studies suggest that ghrelin exerts an inhibitory effect on insulin secretion, resulting in increased circulating glucose levels. Ghrelin may thus be a diabetogenic factor. Obesity-related type 2 diabetes has become an increasingly important health problem, almost reaching epidemic proportions in the world; therefore, antagonists of the ghrelin-GOAT signaling pathway, which will tackle both energy- and glucose homeostasis, may be considered as promising new therapies for this disease.     

Ghrelin、肥胖和阻塞性睡眠呼吸暂停低通气综合征

阻塞性睡眠呼吸暂停低通气综合征（obstructive sleep apnea—hypopnea syndrome。OSAHS）是一种由于睡眠期间反复发生上气道塌陷，导致睡眠时打鼾并伴有呼吸暂停和呼吸表浅，夜间反复发生低氧血症、高碳酸血症和睡眠结构紊乱的疾病，可引起白天嗜睡，易引起高血压、糖尿病、心血管疾病。肥胖是OSAHS最显著的易患因素之一。Ghrelin是一种生长激素促分泌素受体（growth hormone secretagogue receptor，GHSR）的内源性配体，它具有多种生物学功能，如刺激生长激素释放，能增加食欲，调节能量平衡，促进胃酸分泌和胃蠕动。研究发现，ghrelin、肥胖、OSAHS之间存在着密切的关系，本文就三者之间的研究进展作一综述。