Dynamics of in vivo release of molt-inhibiting hormone and crustacean hyperglycemic hormone in the shore crab, Carcinus maenas
Dynamics of in vivo release of molt-inhibiting hormone and crustacean hyperglycemic hormone in the shore crab, Carcinus maenas
复制标题
DOI：
10.1210/en.2005-0859
复制
发表时间：
2005-12-01
期刊：
影响因子：
4.8
通讯作者：
Webster, SG
中科院分区：
文献类型：
--
作者：
Chung, JS;Webster, SG
关于甲壳动物神经肽的释放模式或循环滴度知之甚少，特别是那些与蜕皮激素（蜕皮类固醇）合成、蜕皮抑制激素（MIH）和甲壳动物高血糖激素（CHH）（也是一种适应性激素，在碳水化合物代谢中起重要作用）的调节有关的神经肽。此外，目前接受的模型蜕皮控制是建立在一个未经检验的假设，表明蜕皮可以进行后，MIH滴度下降。因此，我们测量同时循环神经肽配置文件MIH和CHH通过RIA纯化的血淋巴在蜕皮周期在精细的时间尺度在白天/黑夜周期和季节性。对于CHH，我们还确定了生理相关的压力后的释放模式。结果表明，这两种激素是专门和间歇性释放，而不是连续的，在循环中的半衰期显着短，这表明动态和短暂的变化，这两种激素的水平。在蜕皮周期中，MIH滴度没有明显的变化，除了在蜕皮前的后期蜕皮期间MIH的大量和前所未有的增加。这种激素激增的功能尚不清楚。各种应激源（缺氧，温度休克）的治疗表明，CHH的释放发生非常迅速，在几分钟的压力。蜕皮前期（当肠道内分泌细胞合成大量CHH时）应激事件后CHH的释放仅来自窦腺：来自肠道的CHH从不参与应激反应。结果表明，迄今未被怀疑的动力学释放的MIH和CHH，并建议目前接受的模式蜕皮控制必须重新考虑。
Very little is known regarding the release patterns or circulating titers of neuropeptides in crustaceans, in particular those concerned with regulation of molting hormone (ecdysteroid) synthesis, molt-inhibiting hormone (MIH), and crustacean hyperglycemic hormone (CHH), which is also an adaptive hormone, centrally important in carbohydrate metabolism. Furthermore, the currently accepted model of molt control is founded on an untested hypothesis suggesting that molting can proceed only after decline in MIH titer. Accordingly, we measured simultaneous circulating neuropeptide profiles for both MIH and CHH by RIA of purified hemolymph during the molt cycle at fine temporal scale during day/night cycles and seasonally. For CHH we additionally determined release patterns after physiologically relevant stress. Results show that both hormones are released exclusively and episodically, rather than continuously, with notably short half-lives in circulation, suggesting dynamic and short-lived variations in levels of both hormones. During the molt cycle, there are no overt changes in MIH titer, except a massive and unprecedented increase in MIH during late pre-molt, just before ecdysis. The function of this hormone surge is unknown. Treatment with various stressors (hypoxia, temperature shock) showed that CHH release occurs extremely rapidly, within minutes of stress. Release of CHH after stressful episodes during premolt (when gut endocrine cells synthesize large quantities of CHH) is exclusively from the sinus gland: CHH from the gut is never involved in the stress response. The results show a hitherto unsuspected dynamism in release of MIH and CHH and suggest that currently accepted models of molt control must be reconsidered.