Systematic search on a smooth muscle stimulant peptide in mammalian kidney.

在哺乳动物细胞系中未知生物活性肽的调查中，我们在佛波酯处理的人单核细胞系THP-1的培养基中检测到最有效的鸡直肠松弛活性。因此，我们从THP-1的培养基中开始纯化，并分离出四种对鸡直肠具有强松弛作用的肽。通过微序列分析，推断这些肽的氨基酸序列是一系列人C型利钠肽（CNP），从CNP-22的N-末端有几个氨基酸延长。此外，在THP-1细胞中检测到CNP mRNA，并且CNP基因的表达和培养液中CNP浓度被证明通过佛波酯的刺激而大大增加。在THP-1单核细胞系中CNP产生的证明表明CNP还在免疫和血管系统中作为局部化学介质起作用，虽然CNP被认为是一种神经肽，只在中枢神经系统中起作用， 关于我们 本研究还从人嗜铬细胞瘤提取物中发现了一种新的促血小板活化肽，它是一种新的促血小板活化肽。由于这种肽在正常肾上腺髓质以及肾上腺髓质产生的嗜铬细胞瘤组织中丰富，因此将其命名为“肾上腺髓质素”。该肽由52个氨基酸组成，分子内有一个二硫键，与降钙素基因相关肽有一定的同源性。由于肾上腺髓质素在嗜铬细胞瘤组织中含量丰富，因此我们构建了嗜铬细胞瘤cDNA文库，并对编码肾上腺髓质素前体的cDNA克隆进行了分离和测序。人肾上腺髓质素的前体（人前肾上腺髓质素原）长185个氨基酸，包括肾上腺髓质素序列，随后是甘氨酸（酰胺供体）。肾上腺髓质素原（proAM）含有独特的20个氨基酸序列，随后是N-末端区域中的Gly-Lys-Arg。有可能从前体加工出具有酰胺化羧基末端的新型20个残基肽“肾上腺髓质素前体N-末端20肽”（proAM-N20）。RNA印迹分析发现，肾上腺髓质素mRNA在肾上腺髓质、心室、肺、肾和嗜铬细胞瘤中均有高表达，肾上腺髓质素广泛分布于多种组织中，并在血液循环中有一定浓度。提示肾上腺髓质素是一种新的参与循环调控的激素。肾上腺髓质素的出现表明可能存在一种新的循环控制系统。少

In a survey for unknown bioactive peptides in mammalian cell lines, we detected the most potent chick rectum relaxant activity in the culture medium of phorbol ester-treated human monocytic cell line, THP-1. Thus, we started purification from the culture medium of THP-1 and isolated four peptides exhibiting strong relaxant effects on chick rectum. By microsequence analysis, amino acid sequences of these peptides were deduced to be a series of human C-type natriuretic peptides (CNPs) with several amino acid elongations from the N-terminus of CNP-22. Furthermore, CNP mRNA was detected in the THP-1 cells, and expression of CNP gene and CNP concentration in the culture medium were shown to be greatly increased by the stimulation of phorbol ester.The demonstration of CNP production in THP-1 monocytic cell line suggests that CNP also functions as a local chemical mediator in the immune and vascular system, although CNP has been recognized to function as a neuropeptide exclusively in the cent … More ral nervous system.We have also been searching for peptides which may be relevant to circulation control, using an assay system which monitors the elevating activty of platelet cAMP.In the present study, we discovered a novel hypotensive peptide in human pheochromocytoma extract. Since this peptide is abundant in normal adrenal medulla as well as in pheochoromocytoma tissue arising from adrenal medulla, it was designated "adrenomedullin". The peptide, consisting of 52 amino acids, has one intramolecular disulfide bond and shows slight homology with calcitonin gene related peptide. It was found to elicit a potent and long lasting hypotensive effect in anesthetized rat.Since adrenomedullin was abundant in pheochromocytoma tissue, the cDNA library of pheochromocytoma was constructed, and the cDNA clone concoding an adrenomedullin precursor was isolated and sequencd. The precursor for human adrenomedullin (human preproadrenomedullin) is 185 amino acids in length, including an adrenomedullin sequence, followed by a glycine (the amide donor). Proadrenomedullin (proAM) contains a unique twenty amino acid sequence followed by Gly-Lys-Arg in the N- terminal region. It is possible that a novel 20 residues peptide "proadrenomedullin N- terminal 20 peptide" (proAM-N20) with an amidated carboxy teminus is processed from the precursor. By RNA blot anaylysis, human adrenomedullin mRNA was found to be highly expressed in several tissues including adrenal medulla, ventricle, lung and kidney as well as pheochromocytoma.Adrenomedullin was widely distributed in several tissues and circulates in blood in a considerable concentration. These data suggest that adrenomedullin is a new hormone participating in circulation control. Occurrence of adrenomedullin indicates the possible existence of a novel system for circulation control. Less