Acute Hypoxia Induces Enkephalin Production and Release in an Adrenergic Cell Line Model of Neonatal Chromaffin Cell Responses to Hypoxic Stress
Acute Hypoxia Induces Enkephalin Production and Release in an Adrenergic Cell Line Model of Neonatal Chromaffin Cell Responses to Hypoxic Stress
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DOI：
10.1055/s-0038-1641169
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发表时间：
2018-09-01
影响因子：
2
通讯作者：
Evinger, Marian
中科院分区：
文献类型：
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作者：
Calero, Alexa;Villanueva, Hazel;Evinger, Marian
目的：在人类交感神经系统成熟之前，新生儿肾上腺髓质对缺氧的感觉和反应。除了儿茶酚胺释放外，肾上腺髓质还合成和储存阿片肽，特别是脑啡肽（ENK）。然而，尚不清楚急性缺氧是否会引起肾上腺ENK的产生和释放，如在中枢神经系统（CNS）中所见。我们假设急性缺氧刺激了染色质细胞中ENK的合成和释放。研究设计将肾上腺素能小鼠嗜铬细胞瘤细胞（MPC） 10/9/96CR培养于10%氧（O(2)）中，培养间隔长达60分钟。采用Met-ENK酶联免疫吸附试验（ELISA）测定ENK含量和释放量。采用定量逆转录聚合酶链式反应（PCR）分析ENK信使核糖核酸（mRNA）。结果MPC 10/9细胞在10% O(2)中孵育可引起肾上腺素和Met-ENK的快速释放，在15分钟内增加约2倍。减少的[O(2)]也诱导细胞ENK肽含量在60分钟内总体增加（14%）。急性缺氧刺激下Met-ENK的释放伴随着肾上腺素能性染色质细胞培养模型MPC 10/9s中mRNA （ENK）表达的增加。我们推测，降低[O(2)]诱导染色质细胞释放ENK的能力可能影响血压调节和心脏收缩力，从而在新生儿窒息期间提供适应性生存优势。
Objective Prior to maturation of the human sympathetic nervous system, the neonatal adrenal medulla senses and responds to hypoxia. In addition to catecholamine release, the adrenal medulla synthesizes and stores opioid peptides, notably enkephalin (ENK). However, it is not known whether acute hypoxia evokes adrenal ENK production and release, as seen in the central nervous system (CNS). We hypothesize that acute hypoxia stimulates synthesis and release of ENK in chromaffin cells.Study Design Cultures of adrenergic mouse pheochromocytoma cells (MPC) 10/9/96CR were incubated in 10% oxygen (O (2) ) at intervals of up to 60 minutes. ENK content and release were measured by Met-ENK enzyme-linked immunosorbent assay (ELISA). ENK messenger ribonucleic acid (mRNA) was analyzed by quantitative reverse-transcriptase polymerase chain reaction (PCR).Results Incubation of MPC 10/9 cells in 10% O (2) evoked rapid release of epinephrine and of Met-ENK which increased approximately twofold in 15 minutes. Reduced [O (2) ] also induced an overall increase (14%) in cellular ENK peptide content within 60 minutes. Acute hypoxia-stimulated release of Met-ENK was accompanied by increased mRNA (ENK) expression in MPC 10/9s, a cell culture model of adrenergic chromaffin cells.Conclusion We speculate that the ability of reduced [O (2) ] to evoke ENK release from chromaffin cells may influence blood pressure regulation and heart contractility, thereby providing an adaptive survival advantage during neonatal asphyxia.