Programa de Pós-Graduação em Ciências Fisiológicas, Fisiologia Animal Comparada, Universidade Federal do Rio Grande-FURG, Avenida Itália, Km 8, CEP 96201-900 Rio Grande, RS, Brazil; Instituto de Ciências Biológicas, Universidade Federal do Rio Grande-FURG, Avenida Itália, Km 8, CEP 96201-900 Rio Grande, RS, Brazil.
Programa de Pós-Graduação em Aquicultura, Universidade Federal do Rio Grande-FURG, Avenida Itália, Km 8, CEP 96201-900 Rio Grande, RS, Brazil; Instituto de Ciências Biológicas, Universidade Federal do Rio Grande-FURG, Avenida Itália, Km 8, CEP 96201-900 Rio Grande, RS, Brazil.
Fish Shellfish Immunol. 2014 Feb;36(2):519-24. doi: 10.1016/j.fsi.2013.12.022. Epub 2014 Jan 7.
Growth hormone (GH) is an important regulator of immune functions in vertebrates, and it has been intensively reported a series of stimulatory actions of this hormone over on the immune system. Within aquaculture, overexpression of GH has been considered a promising alternative for promoting higher growth rates in organisms of commercial interest. Considering the various pleiotropic effects of GH, there are still few studies that aim to understand the consequences of the excess of GH on the physiological systems. In this context, our goal was to present the effects of the overexpression of GH on immune parameters using a model of zebrafish (Danio rerio) that overexpress this hormone. The results showed that GH transgenic zebrafish had 100% of mortality when immunosuppressed with dexamethasone, revealing a prior weakening of the immune system in this lineage. Morphometric analysis of thymus and head kidney revealed a reduction in the area of these structures in transgenic zebrafish. Moreover, the phenotypic expression of CD3 and CD4 thymocytes was also depreciated in transgenic zebrafish. Furthermore, a decrease was noted in the expression of genes RAG-1 (60%), IKAROS (50%), IL-1β (55%), CD4 (60%) and CD247 (40%), indicating that development parameters, of innate and acquired immunity, are being harmed. Based on these results, it can be concluded that the excess of GH impairs the immune functions in GH transgenic zebrafish, indicating that the maintenance of normal levels of this hormone is essential for the functioning of immunological activities.
生长激素（GH）是脊椎动物免疫系统的重要调节因子，已有大量研究报道了该激素对免疫系统的一系列刺激作用。在水产养殖中，过量表达 GH 被认为是提高商业利益生物体生长速度的一种有前途的替代方法。考虑到 GH 的各种多效性作用，仍有少数研究旨在了解 GH 过量对生理系统的后果。在这种情况下，我们的目标是使用过表达 GH 的斑马鱼（Danio rerio）模型来展示 GH 过表达对免疫参数的影响。结果表明，用地塞米松免疫抑制时，GH 转基因斑马鱼的死亡率为 100%，这表明该品系的免疫系统先前已经减弱。对胸腺和头肾的形态计量分析显示，转基因斑马鱼中这些结构的面积减少。此外，转基因斑马鱼中胸腺细胞 CD3 和 CD4 的表型表达也减少了。此外，还注意到 RAG-1（60%）、IKAROS（50%）、IL-1β（55%）、CD4（60%）和 CD247（40%）的基因表达下降，表明先天和获得性免疫的发育参数受到损害。基于这些结果，可以得出结论，GH 过量会损害 GH 转基因斑马鱼的免疫功能，表明维持正常水平的 GH 对于免疫活性的发挥至关重要。
