Chicken ghrelin: Purification, cDNA cloning, and biological activity
Chicken ghrelin: Purification, cDNA cloning, and biological activity
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DOI：
10.1210/en.2002-220255
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发表时间：
2002-09-01
期刊：
影响因子：
4.8
通讯作者：
Kangawa, K
中科院分区：
文献类型：
--
作者：
Kaiya, H;Van Der Geyten, S;Kangawa, K
在本研究中，我们报道了鸡（Gallus Gallus）新型生长激素释放肽ghrelin的纯化、cDNA克隆和特性。鸡胃饥饿素由26个氨基酸（GSSFLSPTYKNIQQQKDTRKPTARLH）组成，与人类胃饥饿素的序列同源性为54%。位置3的丝氨酸残基（Ser(3)）在鸡和哺乳动物之间是保守的，因为它被正辛酸或正癸酸酰化。鸡胃饥饿素mRNA主要在胃中表达，在胃前室中存在，但在砂囊中不存在。通过RT-PCR分析，在脑、肺和肠中也检测到低水平的表达。在大鼠和雏鸡中施用鸡胃饥饿素可增加血浆生长激素水平，其效力与大鼠或人胃饥饿素相似。此外，与哺乳动物相比，较低剂量的鸡胃促生长素也能提高生长中的小鸡血浆皮质酮水平。目前的结果表明，胃饥饿素对生长激素分泌的刺激作用是进化保守的，而它对鸡肾上腺功能的影响似乎是独特的。
In this study, we report the purification, cDNA cloning, and characterization of the novel growth hormone-releasing peptide, ghrelin, in the chicken (Gallus gallus). Chicken ghrelin is composed of 26 amino acids (GSSFLSPTYKNIQQQKDTRKPTARLH) and possesses 54% sequence identity with human ghrelin. The serine residue at position 3 (Ser(3)) is conserved between the chicken and mammalian species, as its acylation by either n-octanoic or n-decanoic acid. Chicken ghrelin mRNA is predominantly expressed in the stomach, where it is present in the proventriculus but absent in the gizzard. Using RT-PCR analysis, low levels of expression were also detectable in brain, lung, and intestine. Administration of chicken ghrelin increases plasma GH levels in both rats and chicks, with a potency similar to that of rat or human ghrelin. In addition, chicken ghrelin also increases plasma corticosterone levels in growing chicks at a lower dose than in mammals. The present results indicate that the stimulatory effect of ghrelin on GH secretion is evolutionarily conserved, whereas its effect on adrenal function seems to be unique in the chicken.