On the subcellular localization of the polyamines.
On the subcellular localization of the polyamines.
复制标题
关于多胺的亚细胞定位。
DOI：
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发表时间：
1989
期刊：
影响因子：
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通讯作者：
Nikolaus Seiler
中科院分区：
文献类型：
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作者：
S. Sarhan;Nikolaus Seiler
腐胺，亚精胺和精胺测定在大鼠肝脏的核部分，这是通过密度梯度离心在非水介质中，即在避免迁移的水溶性化合物的条件下获得。多胺在细胞核和胞核间室中分布的计算是基于DNA集中在细胞核中的假设。在分馏过程中没有发生多胺的显著损失。从组织和细胞核中多胺的测定结果来看，16-17%的肝精脒和精胺以及约8%的腐胺含量位于细胞核中。细胞核和整个组织中的亚精胺/精胺比率没有显著差异。预处理的动物与鸟氨酸脱羧酶的抑制剂引起腐胺的减少，专门在细胞核隔室，在协议与较高比例的抑制剂在细胞质中。由于大鼠肝脏的核体积约占肝脏总体积的5%，因此精脒和精胺在核中的浓度高于在核间室中的浓度。已发表的多胺的组织化学定位表明非常低的多胺浓度在非分裂的肝脏和HeLa细胞的细胞核，但显着的多胺积累在中期和后期的细胞核。这些结果与以前报道的放射自显影数据，密度梯度离心的基础上的亚细胞定位，并与我们目前的结果不一致。由于亚细胞定位是一个关键问题，在所有试图澄清细胞功能的多胺的仔细修订所涉及的技术在亚细胞多胺定位似乎势在必行。
Putrescine, spermidine and spermine were determined in the nuclear fraction of rat liver which was obtained by density gradient centrifugation in non-aqueous media, i.e. under conditions which avoid migration of water-soluble compounds. Calculations of the distribution of the polyamines between nuclear and extranuclear compartments were based on the assumption that the DNA is concentrated in the nuclei. No significant losses of the polyamines occurred during fractionation. From the polyamine determination in tissue and nuclear fraction it appeared that 16-17% of the liver spermidine and spermine, and about 8% of the putrescine content was localized in the nuclei. The spermidine/spermine-ratios in nuclei and whole tissue were not significantly different. Pretreatment of the animals with inhibitors of ornithine decarboxylase caused a decrease of putrescine exclusively in the extranuclear compartments, in agreement with a higher proportion of the inhibitors in the cytoplasm. Since the nuclear volume of rat liver corresponds to about 5% of total liver volume, the concentration of spermidine and spermine is higher in the nucleus than in extranuclear compartments. Published histochemical localizations of the polyamines suggested very low polyamine concentrations in the nuclei of non-dividing liver and HeLa cells, but dramatic polyamine accumulations in metaphase and anaphase nuclei. These results are in disagreement with previously reported autoradiographic data, subcellular localizations based on density gradient centrifugations, and with our present results. Since subcellular localization is a key issue in all attempts to clarify cellular functions of the polyamines the careful revision of the techniques involved in subcellular polyamine localizations seems imperative.