Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada.
Mol Cell Endocrinol. 2018 Mar 5;463:142-167. doi: 10.1016/j.mce.2017.06.002. Epub 2017 Jun 3.
Gonadotropin-releasing hormone (GnRH) is a major regulator of reproduction through actions on pituitary gonadotropin release and synthesis. Although it is often thought that pituitary cells are exposed to only one GnRH, multiple GnRH forms are delivered to the pituitary of teleost fishes; interestingly this can include the cGnRH-II form usually thought to be non-hypophysiotropic. GnRHs can regulate other pituitary cell-types, both directly as well as indirectly, and multiple GnRH receptors (GnRHRs) may also be expressed in the pituitary, and even within a single pituitary cell-type. Literature on the differential actions of native GnRH isoforms in primary pituitary cells is largely derived from teleost fishes. This review will outline the diversity and complexity of GnRH-GnRHR signal transduction found within vertebrate gonadotropes as well as extra-gonadotropic sites with special emphasis on comparative studies from fish models. The implications that GnRHR transduction mechanisms are GnRH isoform-, function-, and cell-specific are also discussed.
促性腺激素释放激素（GnRH）是通过对垂体促性腺激素释放和合成的作用来调节生殖的主要调节剂。尽管人们通常认为垂体细胞只暴露于一种 GnRH，但多种 GnRH 形式被递送到硬骨鱼类的垂体中；有趣的是，这可能包括通常被认为是非垂体促性腺激素的 cGnRH-II 形式。GnRH 可以直接或间接调节其他垂体细胞类型，并且可能在垂体中表达多种 GnRH 受体（GnRHRs），甚至在单个垂体细胞类型中也可以表达。关于天然 GnRH 同工型在初级垂体细胞中的差异作用的文献主要来自硬骨鱼类。本综述将概述在脊椎动物促性腺激素细胞以及性腺外部位发现的 GnRH-GnRHR 信号转导的多样性和复杂性，特别强调来自鱼类模型的比较研究。还讨论了 GnRHR 转导机制是 GnRH 同工型、功能和细胞特异性的含义。
