Stevens Adam, White Anne
Endocrine Sciences, Faculty of Medical and Human Sciences, University of Manchester, Manchester, M13 9PT, UK.
Results Probl Cell Differ. 2010;50:63-84. doi: 10.1007/400_2009_30.
Adrenocorticotrophic hormone (ACTH) is derived from the prohormone, pro-opiomelanocortin (POMC). This precursor undergoes proteolytic cleavage to yield a number of different peptides which vary depending on the tissue. In the anterior pituitary, POMC is processed to ACTH by the prohormone convertase, PC1 and packaged in secretory granules ready for stimulated secretion. In response to stress, corticotrophin releasing hormone (CRH), stimulates release of ACTH from the pituitary cell which in turn causes release of glucocorticoids from the adrenal gland. In tissues, such as the hypothalamus and skin, ACTH is further processed intracellularly to alpha melanocyte stimulating hormone (alphaMSH) which has distinct roles in these tissues. The prohormone, POMC, is itself released from cells and found in the human circulation at concentrations greater than ACTH. While much is known about the tightly regulated synthesis of POMC, there is still a lot to learn about the mechanisms for differentiating secretion of POMC, and the POMC-derived peptides. Understanding what happens to the POMC released from cells will provide new insights into its function.
促肾上腺皮质激素（ACTH）源自前体激素阿黑皮素原（POMC）。该前体经蛋白水解切割产生多种不同的肽，这些肽因组织而异。在垂体前叶，POMC由前体激素转化酶PC1加工成ACTH，并包装在分泌颗粒中，随时准备受刺激分泌。应激时，促肾上腺皮质激素释放激素（CRH）刺激垂体细胞释放ACTH，进而导致肾上腺释放糖皮质激素。在诸如下丘脑和皮肤等组织中，ACTH在细胞内进一步加工成α-黑素细胞刺激素（α-MSH），其在这些组织中具有不同的作用。前体激素POMC本身从细胞中释放出来，在人体循环中的浓度高于ACTH。虽然人们对POMC严格调控的合成了解很多，但关于POMC及其衍生肽的差异分泌机制仍有很多有待了解。了解从细胞中释放出来的POMC会发生什么，将为其功能提供新的见解。
