Dardente H
School of Biological Sciences, University of Aberdeen, Zoology Building, Tillydrone Avenue, Aberdeen, UK.
J Neuroendocrinol. 2007 Aug;19(8):657-66. doi: 10.1111/j.1365-2826.2007.01564.x.
The pars tuberalis (PT) of the adenohypophysis expresses a high density of melatonin receptors and is thought to be a crucial relay for the actions of melatonin on seasonal rhythmicity of prolactin secretion by the pars distalis (PD). In common with the suprachiasmatic nucleus of the hypothalamus and most other peripheral tissues, the PT rhythmically expresses a range of 'clock genes'. Interestingly, this expression is highly dependent upon melatonin/photoperiod, with several aspects unique to the PT. These observations led to the establishment of a conceptual framework for the encoding of seasonal timing in this tissue. This review summarises current knowledge of the morphological, functional and molecular aspects of the PT and considers its role in seasonal timing. The strengths and weaknesses of current hypotheses that link melatonin action in the PT to its seasonal effect on lactotrophs of the PD are discussed and alternative working hypotheses are suggested.
腺垂体的结节部（PT）表达高密度的褪黑素受体，被认为是褪黑素作用于远侧部（PD）催乳素分泌季节性节律的关键中继站。与下丘脑视交叉上核及大多数其他外周组织一样，PT有节律地表达一系列“时钟基因”。有趣的是，这种表达高度依赖于褪黑素/光周期，且PT有几个独特的方面。这些观察结果为该组织中季节性时间编码建立了一个概念框架。本综述总结了目前关于PT的形态、功能和分子方面的知识，并探讨了其在季节性时间调控中的作用。讨论了当前将PT中褪黑素作用与其对PD催乳细胞的季节性影响联系起来的假说的优缺点，并提出了其他可行的假说。
