Translation of heart preproenkephalin mRNA and secretion of enkephalin peptides from cultured cardiac myocytes.
Translation of heart preproenkephalin mRNA and secretion of enkephalin peptides from cultured cardiac myocytes.
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心脏前脑啡肽原 mRNA 的翻译和培养心肌细胞脑啡肽肽的分泌。
DOI：
10.1152/ajpheart.1992.263.5.h1560
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发表时间：
1992
期刊：
影响因子：
--
通讯作者：
Claycomb,WC
中科院分区：
文献类型：
--
作者：
Springhorn,JP;Claycomb,WC
此前已有研究表明，大鼠心肌中含有异常高水平的前脑啡肽原信使核糖核酸(PpEnk MRNA)。我们最近已经确定，在大鼠的心室肌组织和培养的心肌细胞中，ppEnk mRNA的水平受到发育和激素的调节(J.P.Springhorn和W.C.Claycomb)。生物化学。J.258：73-77,1989)。在目前的研究中，我们利用核糖核酸酶保护实验证明了心脏ppEnk mRNA在5‘端的结构与脑ppEnk mRNA相同，并且心脏ppEnk mRNA可以使用兔网织红细胞裂解物系统在体外翻译。体外合成的前脑啡肽原与针对前脑啡肽原羧基末端7个氨基酸的多克隆抗体进行免疫沉淀。我们还通过放射免疫分析证实，培养的新生和成年大鼠心肌细胞都能分泌脑啡肽。这种分泌与时间呈线性关系，并可被佛波酯(PMA)和3‘，5’-环磷酸腺苷(CAMP)刺激。柱层析结果表明，cAMP可诱导新生大鼠心肌细胞分泌甲基脑啡肽-Arg6-Phe7，而PMA+3-异丁基-1-甲基黄嘌呤可诱导成年大鼠心肌细胞分泌甲基5-脑啡肽。这些研究证实，心室肌ppEnk mRNA是可以翻译的，脑啡肽是由心室肌细胞分泌的。
Rat ventricular cardiac muscle has previously been shown to contain exceptionally high levels of preproenkephalin mRNA (ppEnk mRNA). We have recently determined that the level of ppEnk mRNA is developmentally and hormonally regulated in rat ventricular cardiac muscle tissue and in cultured myocytes (J. P. Springhorn and W. C. Claycomb. Biochem. J. 258: 73-77, 1989). We demonstrate in the current study that heart ppEnk mRNA is structurally identical at the 5' end to brain ppEnk mRNA using a ribonuclease protection assay and that heart ppEnk mRNA can be translated in vitro using a rabbit reticulocyte lysate system. In vitro synthesized preproenkephalin peptides were immunoprecipitated with a polyclonal antibody directed to the carboxy-terminal seven amino acids of preproenkephalin. We have also established by radioimmunoassay that enkephalin-containing peptides are secreted from cultured neonatal and adult rat ventricular cardiac muscle cells. This secretion is linear with respect to time and can be stimulated by phorbol 12-myristate 13-acetate (PMA) and adenosine 3',5'-cyclic monophosphate (cAMP). It was determined by column chromatography that cAMP induced neonatal rat ventricular cardiac muscle cells to secrete Met5-enkephalin-Arg6-Phe7, whereas PMA plus 3-isobutyl-1-methylxanthine induced adult rat ventricular cardiac muscle cells to secrete Met5-enkephalin. These studies establish that ventricular heart muscle ppEnk mRNA can be translated and that enkephalin peptides are secreted from ventricular cardiac muscle cells.