Vasopressin gene products are colocalised with corticotrophin‐releasing factor within neurosecretory vesicles in the external zone of the median eminence of the Japanese macaque monkey ( Macaca fuscata )
Vasopressin gene products are colocalised with corticotrophin‐releasing factor within neurosecretory vesicles in the external zone of the median eminence of the Japanese macaque monkey ( Macaca fuscata )
复制标题
加压素基因产物与促肾上腺皮质激素释放因子共定位于日本猕猴（Macaca fuscata）正中隆起外部区域的神经分泌小泡内
DOI：
10.1111/jne.12875
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发表时间：
2020
影响因子：
3.2
通讯作者：
Sakamoto Hirotaka
中科院分区：
文献类型：
--
作者：
Otubo Akito;Kawakami Natsuko;Maejima Sho;Ueda Yasumasa;Morris John F.;Sakamoto Tatsuya;Sakamoto Hirotaka
精氨酸加压素（AVP）与促肾上腺皮质激素释放因子（CRF）一起从下丘脑室旁核（PVH）的小细胞神经元末梢释放到门静脉毛细血管中时，促进应激啮齿动物促肾上腺皮质激素（ACTH）的分泌。AVP基因编码一个前肽前体，包含AVP、AVP相关的神经垂体后叶素II（NPII）和一个糖肽和肽素，尽管目前还不清楚和肽素是否总是从神经垂体后叶素上裂解，以及NPII和/或和肽素是否在垂体中有任何功能作用。此外，对于灵长类动物，目前尚不清楚CRF，AVP，NPII和和肽素是否都在室旁CRF神经元轴突末端区域的神经分泌囊泡中共存。因此，我们通过荧光和免疫金免疫细胞化学研究了这些肽在未应激的日本猕猴（Macaca fuscata）的CRF和AVP产生细胞中的细胞和亚细胞关系。逆转录-聚合酶链反应分析显示CRF和AVP mRNA在猴PVH中均有表达。正如预期的那样，在PVH和视上核的大细胞神经元中，在NPII免疫反应（产生AVP）神经元中基本上没有检测到CRF免疫反应。免疫荧光显示，在PVH的小细胞部分，NPII在众多CRF免疫反应性神经元胞体的亚群（约39%）中可检测到，而在外正中隆起中，NPII在CRF静脉曲张中更为突出（约52%）。正中隆起的三重免疫电子显微镜显示在含CRF轴突的致密核心囊泡中存在NPII和和肽素免疫反应性。结果与以下观点一致：AVP前肽被加工，NPII和和肽素共定位于灵长类动物正中隆起的下丘脑-垂体CRF轴突中。CRF、AVP和和肽素都共同包装在猴的神经分泌囊泡中，因此可能共同释放到门静脉毛细血管血液中，以放大灵长类动物垂体前叶的ACTH释放。
Arginine vasopressin (AVP), when released into portal capillaries with corticotrophin‐releasing factor (CRF) from terminals of parvocellular neurones of the hypothalamic paraventricular nucleus (PVH), facilitates the secretion of adrenocorticotrophic hormone (ACTH) in stressed rodents. TheAVPgene encodes a propeptide precursor containing AVP, AVP‐associated neurophysin II (NPII), and a glycopeptide copeptin, although it is currently unclear whether copeptin is always cleaved from the neurophysin and whether the NPII and/or copeptin have any functional role in the pituitary. Furthermore, for primates, it is unknown whether CRF, AVP, NPII and copeptin are all colocalised in neurosecretory vesicles in the terminal region of the paraventricular CRF neurone axons. Therefore, we investigated, by fluorescence and immunogold immunocytochemistry, the cellular and subcellular relationships of these peptides in the CRF‐ and AVP‐producing cells in unstressed Japanese macaque monkeys (Macaca fuscata). Reverse transcription‐polymerase chain reaction analysis showed the expression of both CRF and AVP mRNAs in the monkey PVH. As expected, in the magnocellular neurones of the PVH and supraoptic nucleus, essentially no CRF immunoreactivity could be detected in NPII‐immunoreactive (AVP‐producing) neurones. Immunofluorescence showed that, in the parvocellular part of the PVH, NPII was detectable in a subpopulation (approximately 39%) of the numerous CRF‐immunoreactive neuronal perikarya, whereas, in the outer median eminence, NPII was more prominent (approximately 52%) in the CRF varicosities. Triple immunoelectron microscopy in the median eminence demonstrated the presence of both NPII and copeptin immunoreactivity in dense‐cored vesicles of CRF‐containing axons. The results are consistent with an idea that the AVP propeptide is processed and NPII and copeptin are colocalised in hypothalamic‐pituitary CRF axons in the median eminence of a primate. The CRF, AVP and copeptin are all co‐packaged in neurosecretory vesicles in monkeys and are thus likely to be co‐released into the portal capillary blood to amplify ACTH release from the primate anterior pituitary.