Prolactin Regulation by the Pars Tuberalis

许多荷尔蒙遵循季节节律，但没有一种激素比催乳素更有节律。催乳素是由位于大脑底部的脑下垂体腺分泌的，夏天高，冬天低。这些季节性变化是由日光的变化驱动的，而日光的变化被另一种荷尔蒙--褪黑素--转化为体内的化学信号。褪黑素作用于脑下垂体的一个神秘部分，即结节部，以调节一种未知因素的分泌，而这种未知因素反过来又推动季节性催乳素的释放。在目前的项目中，假设这一未知因素的身份是一种“速激肽”。本项目将以绵羊为模型，研究结节部速激肽的释放以及这些速激肽对一年中不同季节催乳素分泌的影响。预计速激肽的产生或受体调节将因季节而异，因此，其调节催乳素释放的能力将取决于季节。这项研究将推动一个重要的基础科学问题--确定神秘的结节分泌什么。这项研究还可能解决为什么结节部色恐惧症肿瘤会导致高催乳素血症，并解决哺乳动物高催乳素血症和不孕症之间的共同联系。该项目将为学生提供独特的培训机会，这些学生将有望在国内和国际会议上介绍他们的研究结果，这些学生将有机会成为同行评议出版物的共同作者。

Many hormones follow seasonal rhythms, but none more so than prolactin. Prolactin is secreted by the pituitary gland at the base of the brain and is high in summer and low in winter. These seasonal changes are driven by the changes in daylight that are transformed into a chemical signal in the body by another hormone, melatonin. Melatonin acts on an enigmatic subdivision of the pituitary gland, the pars tuberalis, to regulate the secretion of an unknown factor that, in turn, drives seasonal prolactin release. In the current project it is hypothesized that the identity of this unknown factor is a "tachykinin". Using sheep as a model, this project will investigate the release of tachykinins by the pars tuberalis and the effect of these tachykinins on prolactin secretion during the different seasons of the year. It is expected that tachykinin production or receptor regulation will differ between seasons and, accordingly, its ability to modulate prolactin release will be seasonally dependent. This research will drive forward an important basic scientific question - establishing what the enigmatic pars tuberalis secretes. This research may also resolve why chromophobic tumors of the pars tuberalis region induce hyperprolactinemia and address the common link between hyperprolactinemia and infertility in mammals. The project will offer unique training opportunities for students who will be expected to present their findings at national and international conferences and these students will have the opportunity to become co-authors on peer-reviewed publications.