Evidence that growth hormone exerts a feedback effect on stomach ghrelin production and secretion
Evidence that growth hormone exerts a feedback effect on stomach ghrelin production and secretion
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DOI：
10.1177/153537020322800907
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发表时间：
2003-10-01
影响因子：
3.2
通讯作者：
Greeley, GH
中科院分区：
文献类型：
--
作者：
Qi, XA;Reed, J;Greeley, GH
Ghrelin是最近发现的一种胃激素，它能有效地刺激垂体生长激素（GH）的分泌。这些实验的目的是检验胃-生长激素释放肽-垂体-GH轴存在的假设，其中全身GH水平的升高或降低将分别对胃生长激素释放肽稳态产生负反馈或正反馈作用。在大鼠中，GH给药显着降低胃饥饿素mRNA水平和血浆饥饿素水平。在生长激素释放激素（GHRH）转基因小鼠中，GHRH过表达降低胃ghrelin肽水平时，与对照组小鼠相比。与年轻大鼠（5个月）相比，老年大鼠（25个月）胃生长素mRNA和肽水平以及血浆生长素水平均降低。由于老年大鼠GH分泌减少，胃Ghrelin产生和分泌增加可能反映了GH对胃Ghrelin，稳态，分泌的反馈减少。总之，这些研究结果表明，内源性垂体生长激素对胃生长激素释放肽稳态发挥反馈作用，并支持胃-生长激素释放肽-垂体生长激素轴存在的假设。
Ghrelin is a recently discovered stomach hormone that stimulates pituitary growth hormone (GH) secretion potently. The purpose of these experiments was to test the hypothesis that a stomach-ghrelin-pituitary-GH axis exists in which either an elevation or reduction in systemic GH levels will exert a negative or positive feedback action, respectively, on stomach ghrelin homeostasis. In rats, GH administration decreased stomach ghrelin mRNA levels and plasma ghrelin levels significantly. In GH-releasing hormone (GHRH) transgenic mice, GHRH overexpression decreased stomach ghrelin peptide levels when compared with control mice. In aged rats (25 months) stomach ghrelin mRNA and peptide levels and plasma ghrelin levels were decreased when compared with young rats (5 months). Because GH secretion is reduced in aged rats, the elevated stomach ghrelin production and secretion may reflect a decreased GH feedback on stomach ghrelin, homeostasis, an secretion. Together, these findings suggest that endogenous pituitary GH exerts a feedback action on stomach ghrelin homeostasis and support the hypothesis that a stomach-ghrelin-pituitary GH axis exists.