Environmental control of kisspeptin: Implications for seasonal reproduction
Environmental control of kisspeptin: Implications for seasonal reproduction
复制标题
DOI：
10.1210/en.2006-1249
复制
发表时间：
2007-03-01
期刊：
影响因子：
4.8
通讯作者：
Demas, Gregory E.
中科院分区：
文献类型：
--
作者：
Greives, Timothy J.;Mason, Alex O.;Demas, Gregory E.
KiSS-1 基因编码肽激素 Kisspeptin，它通过直接刺激 GnRH 神经元活性，充当生殖轴的主要正调节因子。为了深入了解 Kisspeptin 在整合和传递生殖相关刺激至 GnRH 系统方面的潜在作用，我们研究了与生殖状态光周期变化相关的 Kisspeptin 肽表达变化以及垂体和性腺对外周 Kisspeptin 注射的反应。季节性繁殖的啮齿动物的繁殖状态会随着日照长度的变化而发生明显的波动。与其他啮齿动物一样，大多数雄性西伯利亚仓鼠（Phodopus sungorus）在暴露于短日照后表现出繁殖能力下降。然而，一部分个体无法对日长信息做出反应，并维持其生殖功能。我们利用这些个体差异来研究 Kisspeptin 是否可以在外部刺激和生殖系统之间的界面发挥作用。长时间暴露于短日后，具有静止生殖轴的动物前腹侧室周核中的 Kisspeptin 细胞标记显着减少，但弓状核中的 Kisspeptin 免疫反应性染色强烈。相比之下，具有功能性生殖系统的动物在前腹侧室周核中表现出大量的 Kisspeptin 免疫反应性神经元，但在弓状核中表达很少。无论光周期或生殖状态如何，Kisspeptin 注射均显着升高 LH 高于注射前水平。总的来说，这些发现表明 Kisspeptin 在协调和向生殖轴传递环境相关信息方面发挥着重要作用，并且该肽在调节生殖功能的季节性变化中也发挥着重要作用。
The KiSS-1 gene encodes the peptide hormone kisspeptin, which acts as a principal positive regulator of the reproductive axis by directly stimulating GnRH neuron activity. To gain insight into a potential role for kisspeptin in integrating and relaying reproductively relevant stimuli to the GnRH system, we investigated changes in kisspeptin peptide expression associated with photoperiodic changes in reproductive state as well as pituitary and gonadal responses to peripheral kisspeptin injections. Seasonally breeding rodents undergo pronounced fluctuations in reproductive state in response to changing day lengths. In common with other rodent species, a majority of male Siberian hamsters ( Phodopus sungorus) exhibit reproductive decline after exposure to short-day lengths. A subset of individuals fails to respond to day length information, however, and maintains their reproductive function. We exploited these individual differences to examine whether kisspeptin may act at the interface between external stimuli and the reproductive system. After extended exposure to short days, animals with a quiescent reproductive axis displayed a marked reduction in kisspeptin cell labeling in the anteroventral periventricular nucleus but robust kisspeptin-immunoreactive staining in the arcuate nucleus. In contrast, animals with functional reproductive systems displayed high numbers of kisspeptin- immunoreactive neurons in the anteroventral periventricular nucleus but a paucity of expression in the arcuate nucleus. Kisspeptin injections significantly elevated LH over preinjection levels regardless of photoperiod or reproductive state. Collectively, these findings suggest an important role for kisspeptin in coordinating and relaying environmentally relevant information to the reproductive axis as well as a role for this peptide in regulating seasonal changes in reproductive function.