Seasonal changes in concentrations of plasma LH and prolactin associated with the advance in the development of photorefractoriness and molt by high temperature in the starling
Seasonal changes in concentrations of plasma LH and prolactin associated with the advance in the development of photorefractoriness and molt by high temperature in the starling
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DOI：
10.1016/j.ygcen.2010.02.004
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发表时间：
2010-05-15
影响因子：
2.7
通讯作者：
Sharp, Peter J.
中科院分区：
文献类型：
--
作者：
Dawson, Alistair;Sharp, Peter J.
在一项对椋鸟（Sturnus vulgaris）的光周期模拟年周期的研究中，温度对睾丸成熟的时间或速度没有影响，但高温导致睾丸退化和蜕皮的时间提前（Dawson，2005）。这项研究询问，对较高温度的响应而导致的早期性腺退化是否代表了中枢神经内分泌对温度的反应，其次，催乳素是否在早期退化中发挥了作用。将阉割的八哥放在 8 或 18 摄氏度的模拟年度光周期中。测量循环黄体生成素和催乳素浓度，并记录婚后换毛的进展情况，作为光耐火性发展的外部指标。此外，2005 年的研究还测量了从完整雄性和雌性椋鸟身上采集的样本中的血浆催乳素。在阉割的鸟类中。在 18 摄氏度时，LH 浓度提前三周下降。这些鸟的换羽时间也与早期研究中的雄性和雌性相同，提前了三周。这表明，由较高温度引起的退化进展可能是由中枢神经内分泌机制引起的，即光耐火性的进步，而不是性腺水平的影响。温度对三周前18℃催乳素峰值的变化有非常显着的影响。然而，在光不应期出现之前，两个温度之间的催乳素没有明显一致的显着差异，因此光不应期的进展可能不是由催乳素介导的。较高的温度导致催乳素显着提前下降，这可能与蜕皮的提前有关。 (C) 2010 Elsevier Inc. 保留所有权利。
In a study on starlings (Sturnus vulgaris) kept on a simulated annual cycle in photoperiod, temperature had no effect on the timing or rate of testicular maturation but high temperature resulted in an advance in the timing of testicular regression and molt (Dawson, 2005). This study asks whether the earlier gonadal regression in response to higher temperature represents a central neuroendocrine response to temperature, and secondly, whether prolactin plays a role in the earlier regression. Castrated starlings were kept on a simulated annual cycle of photoperiod at either 8 or 18 degrees C. Circulating LH and prolactin concentrations were measured and the progress of the post-nuptial molt was recorded as an external indicator of the development of photorefractoriness. Additionally plasma prolactin was measured in samples taken from intact male and female starlings in the 2005 study. In castrated birds. LH concentrations decreased three weeks earlier at 18 degrees C. These birds also showed the same three week advance in molt as males and females in the earlier study. This demonstrates that the advance in regression caused by higher temperatures probably results from a central neuroendocrine mechanism, i.e., an advance in photorefractoriness, rather than an effect at the level of the gonads. Temperature had a highly significant effect on the changes in prolactin peak prolactin occurred three weeks earlier at 18 degrees C. However, there was no clear consistent significant difference in prolactin between the two temperatures in advance of the onset of photorefractoriness, so the advance in photorefractoriness may not be mediated by prolactin. The higher temperature resulted in a significantly earlier decrease in prolactin and this may be causally related to the advance in molt. (C) 2010 Elsevier Inc. All rights reserved.