Department of Biological Sciences, North Dakota State University, Fargo, ND 58108, USA.
Comp Biochem Physiol A Mol Integr Physiol. 2012 Nov;163(3-4):231-45. doi: 10.1016/j.cbpa.2012.08.003. Epub 2012 Aug 14.
The growth hormone (GH)-insulin-like growth factor (IGF) system plays a major role in coordinating the growth of vertebrates including fish. Considerable research on the regulation of growth has focused on the production and secretion of GH from the pituitary. This review will synthesize recent work on regulating extrapituitary aspects of the GH-IGF system, which includes GH binding proteins (GHBP), GH receptors (GHR), IGF binding protein (IGFBP), and IGF receptors (IGFR). These components are widely distributed and they interact to coordinate growth as well as a host of other biological processes such as metabolism, osmoregulation, reproduction, behavior, and immunity. The GH-IGF system of fish is particularly interesting and complex because it consists of multiple subtypes of GHRs, IGFRs, and IGFBPs that arose through gene duplication events associated with the evolution of the teleost lineage. Peripheral regulation of the GH-IGF system results from adjusting peripheral sensitivity to GH and IGFs as well as from modulating the bioavailability and actions of GH and IGFs in target cells. Numerous chemicals, including hormones such as growth hormone, insulin, somatostatin, and sex steroids as well as a variety of transcription factors, proteases, and phosphatases, regulate the synthesis and activity of GHRs, GHBPs, IGFRs, and IGFBPs as well as the synthesis, secretion, and bioavailability of IGFs. In addition, numerous environmental factors such as nutritional state, photoperiod, stress, and temperature have dramatic effects on the expression and activity of peripheral components of the GH/IGF system. The complex regulation of these system components appears to be both organism- and tissue-specific.
生长激素（GH）-胰岛素样生长因子（IGF）系统在协调包括鱼类在内的脊椎动物的生长中起着重要作用。大量关于生长调节的研究集中在垂体GH 的产生和分泌上。本综述将综合最近关于调节 GH-IGF 系统的垂体外部分的工作，包括 GH 结合蛋白（GHBP）、GH 受体（GHR）、IGF 结合蛋白（IGFBP）和 IGF 受体（IGFR）。这些成分分布广泛，它们相互作用以协调生长以及许多其他生物学过程，如代谢、渗透调节、繁殖、行为和免疫。鱼类的 GH-IGF 系统特别有趣和复杂，因为它由与硬骨鱼谱系进化相关的基因复制事件产生的多种 GHRs、IGFRs 和 IGFBPs 组成。GH-IGF 系统的外周调节是通过调节外周对 GH 和 IGFs 的敏感性以及调节 GH 和 IGFs 在靶细胞中的生物利用度和作用来实现的。许多化学物质，包括生长激素、胰岛素、生长抑素和性类固醇等激素以及各种转录因子、蛋白酶和磷酸酶，调节 GHRs、GHBP、IGFR 和 IGFBP 的合成和活性以及 IGFs 的合成、分泌和生物利用度。此外，许多环境因素，如营养状态、光周期、应激和温度，对 GH/IGF 系统外周成分的表达和活性有显著影响。这些系统成分的复杂调节似乎具有组织特异性和组织特异性。
