The effects of in ovo rhIGF-I administration on expression of the growth hormone secretagogue receptor (GHSR) during chicken embryonic development.
The effects of in ovo rhIGF-I administration on expression of the growth hormone secretagogue receptor (GHSR) during chicken embryonic development.
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卵内 rhIGF-I 给药对鸡胚胎发育过程中生长激素促分泌素受体 (GHSR) 表达的影响。
DOI：
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发表时间：
2004
期刊：
影响因子：
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通讯作者：
J. Killefer
中科院分区：
文献类型：
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作者：
S. Gahr;H. Kocamiş;J. Richter;J. Killefer
生长激素的分泌受一对下丘脑因子的控制，即生长激素释放激素和生长抑素。生长激素促分泌素受体（GHSR）及其内源性配体代表了调节生长激素释放的第三种新方法。早期鸡胚胎发育被认为不依赖于GH。然而，最近的证据表明，外周GH分泌在胚胎发育过程中具有旁分泌/自分泌功能。在目前的研究中，我们使用的逆转录聚合酶链反应，以确定在胚胎发育过程中的GHSR的表达模式和卵内重组人（RH）IGF-I管理对其表达模式的影响。在胚胎第3天，每个胚胎用100 ng rhIGF-I的10 mM乙酸溶液和0.1% BSA注射一次卵。从胚胎第0-6天（E）的整个胚胎（n=6/天）、E7- E8的胸/腹半胚胎（n= 6/天）和E9-E20的胸肌（n= 4/天）分离总RNA。我们发现GHSR的表达在E0-E4期间较低，随后在E5时增加，并在E17时保持恒定。GHSR表达在E18增加，然后在E20减少。在rhIGF-I处理的胚胎中发现了类似的模式，除了E8时GHSR表达显著增加。这些数据表明，GHSR可能是积极的调节生长激素分泌在早期胚胎发育过程中，IGF-I管理后的GHSR基因的上调可能有一个重要的作用，在确定出生后肌肉生长。
Growth hormone secretion is under the control of a pair of hypothalamic factors, growth hormone releasing hormone and somatostatin. The growth hormone secretagogue receptor (GHSR) and its endogenous ligand represent a novel third method regulating the release of growth hormone. Early chicken embryonic development has been proposed to be independent of GH. However, recent evidence shows that peripheral GH secretion has paracrine/autocrine functions during embryonic development. In the current study, we used the reverse-transcriptase polymerase chain reaction to determine the expression pattern of the GHSR during embryonic development and the effects of in ovo recombinant human (rh) IGF-I administration on its expression pattern. Eggs were injected once with 100 ng rhIGF-I in 10 mM acetic acid, and 0.1% BSA per embryo on embryonic day 3. Total RNA was isolated from whole embryos on embryonic day (E) 0-6 (n=6 per day), thoracic/abdominal halves of the embryos on E7- E8 (n= 6 per day) and Pectoralis muscle on E9-E20 (n= 4 per day). We found that GHSR expression was low during E0-E4, followed by an increase on E5 and remained constant through E17. GHSR expression then increased on E18 before reducing on E20. A similar pattern was found in the rhIGF-I treated embryos with the exception of a significant increase in GHSR expression on E8. These data indicate that the GHSR may be active in regulating GH secretion during early embryonic development, and upregulation of the GHSR gene following IGF-I administration may have an important role in the determination of postnatal muscle growth.