Department of Experimental Medicine, Sapienza University, Rome, Italy.
Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy.
Andrology. 2021 Jan;9(1):168-184. doi: 10.1111/andr.12918. Epub 2020 Oct 23.
The hypothalamic-pituitary-gonadal (HPG) and hypothalamic-pituitary-somatotropic (HPS) axes are strongly interconnected. Interactions between these axes are complex and poorly understood. These interactions are characterized by redundancies in reciprocal influences at each level of regulation and the combination of endocrine and paracrine effects that change during development.
To comprehensively review the crosstalk between the HPG and HPS axes and related pathological and clinical aspects during various life stages of male subjects.
A thorough search of publications available in PubMed was performed using proper keywords.
Molecular studies confirmed the expressions of growth hormone (GH) and insulin-like growth factor-I (IGF-I) receptors on the HPG axis and reproductive organs, indicating a possible interaction between HPS and HPG axes at various levels. Insulin growth factors participate in sexual differentiation during fetal development, indicating that normal HPS axis activity is required for proper testicular development. IGF-I contributes to correct testicular position during minipuberty, determines linear growth during childhood, and promotes puberty onset and pace through gonadotropin-releasing hormone activation. IGF-I levels are high during transition age, even when linear growth is almost complete, suggesting its role in reproductive tract maturation. Patients with GH deficiency (GHD) and insensitivity (GHI) exhibit delayed puberty and impaired genital development; replacement therapy in such patients induces proper pubertal development. In adults, few studies have suggested that lower IGF-I levels are associated with impaired sperm parameters.
The role of GH-IGF-I in testicular development remains largely unexplored. However, it is important to evaluate gonadic development in children with GHD. Additionally, HPS axis function should be evaluated in children with urogenital malformation or gonadal development alterations. Correct diagnosis and prompt therapeutic intervention are needed for healthy puberty, attainment of complete gonadal development during transition age, and fertility potential in adulthood.
下丘脑-垂体-性腺（HPG）和下丘脑-垂体-生长轴（HPS）之间存在紧密的相互联系。这些轴之间的相互作用非常复杂，目前尚未完全了解。这些相互作用的特点是在每个调节水平上的相互影响存在冗余，并且内分泌和旁分泌效应的组合在发育过程中发生变化。
全面综述男性在各个生命阶段的 HPG 和 HPS 轴之间的相互作用以及相关的病理和临床方面。
使用适当的关键词在 PubMed 中进行了全面的文献检索。
分子研究证实了生长激素（GH）和胰岛素样生长因子-I（IGF-I）受体在 HPG 轴和生殖器官上的表达，这表明 HPS 和 HPG 轴在各个水平上可能存在相互作用。胰岛素生长因子参与胎儿发育过程中的性分化，表明正常的 HPS 轴活性是睾丸正常发育所必需的。IGF-I 有助于在迷你青春期期间正确定位睾丸，决定儿童期的线性生长，并通过促性腺激素释放激素的激活来促进青春期的开始和速度。IGF-I 水平在青春期过渡期间较高，即使线性生长几乎完成，这表明其在生殖道成熟中的作用。GH 缺乏症（GHD）和不敏感症（GHI）患者表现出青春期延迟和生殖器发育受损；此类患者的替代治疗可诱导适当的青春期发育。在成年人中，一些研究表明，较低的 IGF-I 水平与精子参数受损有关。
GH-IGF-I 在睾丸发育中的作用仍在很大程度上未被探索。然而，评估 GHD 儿童的性腺发育非常重要。此外，应在患有泌尿生殖系统畸形或性腺发育改变的儿童中评估 HPS 轴功能。为了实现健康的青春期、在青春期过渡期间实现完全性腺发育以及成年后的生育能力，需要正确诊断和及时治疗干预。
