Division of Neuroendocrinology, Institute of Anatomy, University of Zürich, Winterthurerstr. 190, 8057 Zürich, Switzerland.
J Fish Biol. 2010 Apr;76(6):1233-54. doi: 10.1111/j.1095-8649.2010.02605.x.
Insulin-like growth factor-I (IGF-I) is a key component of the complex system that regulates differentiation, development, growth and reproduction of fishes. The IGF-I gene is mainly expressed in the liver that represents the principal source of endocrine IGF-I but also in numerous other organs where the hormone most probably acts in an autocrine-paracrine manner. The primary stimulus for synthesis and release of IGF-I is growth hormone (GH) from the anterior pituitary. Thus, in analogy to mammals, it is usual to speak of a fish 'GH-IGF-I axis'. The GH-IGF-I system is affected by changes in the environment and probably represents a target of endocrine disrupting compounds (EDC) that impair many physiological processes in fishes. Thus, the review deals with the influences of changes in different environmental factors, such as food availability, temperature, photoperiod, season, salinity and EDCs, on GH gene expression in pituitary, IGF-I gene expression in liver and extrahepatic sites and the physiological effects resulting from the evoked alterations in endocrine and local IGF-I. Environmental influences certainly interact with each other but for convenience of the reader they will be dealt with in separate sections. Current trends in GH-IGF-I research are analysed and future focuses are suggested at the end of the sections.
胰岛素样生长因子-I（IGF-I）是调节鱼类分化、发育、生长和繁殖的复杂系统的关键组成部分。IGF-I 基因主要在肝脏中表达，肝脏是内分泌 IGF-I 的主要来源，但也在许多其他器官中表达，在这些器官中，激素可能以自分泌-旁分泌的方式发挥作用。IGF-I 的合成和释放的主要刺激来自垂体前叶的生长激素（GH）。因此，与哺乳动物类似，通常将鱼类的“GH-IGF-I 轴”称为“GH-IGF-I 轴”。GH-IGF-I 系统受环境变化的影响，可能是内分泌干扰化合物（EDC）的靶标，这些化合物会损害鱼类的许多生理过程。因此，本综述讨论了不同环境因素（如食物供应、温度、光周期、季节、盐度和 EDC）变化对垂体中 GH 基因表达、肝脏和肝外部位 IGF-I 基因表达以及内分泌和局部 IGF-I 变化引起的生理效应的影响。环境影响肯定会相互作用，但为了方便读者，它们将在单独的部分中讨论。在各部分的结尾处分析了 GH-IGF-I 研究的当前趋势，并提出了未来的重点。
