Metz Juriaan R, Huising Mark O, Meek Johannes, Taverne-Thiele Anja J, Wendelaar Bonga Sjoerd E, Flik Gert
Department of Animal Physiology, Faculty of Science, University of Nijmegen, Toernooiveld 1, 6525 ED Nijmegen, The Netherlands.
J Endocrinol. 2004 Jul;182(1):23-31. doi: 10.1677/joe.0.1820023.
Adrenocorticotropic hormone (ACTH) takes a central role in the hypothalamo-pituitary-interrenal axis (HPI axis), which is activated during stress. ACTH is produced by the corticotrope cells of the pituitary pars distalis (PD) and is under control of factors from the nucleus preopticus (NPO). The distribution of ACTH in the hypothalamo-pituitary system in common carp (Cyprinus carpio L.) was assessed by immunohistochemistry. ACTH and beta-endorphin immunoreactivity was observed in the ACTH cells in the PD and in the NPO. Nerve fibers, originating from the NPO and projecting to the pituitary gland, contain beta-endorphin, but not ACTH, and these fibers either control the pituitary pars intermedia (PI) through beta-endorphin or release it to the blood. The release of pituitary ACTH (studied in a superfusion setup) must in vivo be under predominant inhibitory control of dopamine. Release of ACTH is stimulated by corticotropin-releasing hormone, but only when ACTH cells experience dopaminergic inhibition. The expression of the precursor pro-opiomelanocortin in (POMC) NPO, PD and PI was studied in an acute restraint stress paradigm by real-time quantitative polymerase chain reaction (RQ-PCR). POMC gene expression is upregulated in these three key tissues of the hypothalamo-pituitary complex, revealing a hitherto unforeseen complex role for POMC-derived peptides in the regulation of responses to stress.
促肾上腺皮质激素（ACTH）在下丘脑 - 垂体 - 肾间轴（HPI轴）中起核心作用，该轴在应激期间被激活。ACTH由垂体远侧部（PD）的促肾上腺皮质激素细胞产生，并受视前核（NPO）因子的控制。通过免疫组织化学评估了鲤鱼（Cyprinus carpio L.）下丘脑 - 垂体系统中ACTH的分布。在PD和NPO的ACTH细胞中观察到ACTH和β - 内啡肽免疫反应性。起源于NPO并投射到垂体的神经纤维含有β - 内啡肽，但不含ACTH，这些纤维要么通过β - 内啡肽控制垂体中间部（PI），要么将其释放到血液中。垂体ACTH的释放（在灌注实验中研究）在体内必须主要受多巴胺的抑制性控制。促肾上腺皮质激素释放激素刺激ACTH的释放，但仅当ACTH细胞经历多巴胺能抑制时才会如此。通过实时定量聚合酶链反应（RQ-PCR）在急性束缚应激范式中研究了前阿黑皮素原（POMC）在NPO、PD和PI中的表达。POMC基因在这三个下丘脑 - 垂体复合体的关键组织中表达上调，揭示了POMC衍生肽在应激反应调节中迄今未被预见的复杂作用。
