Ouabain is secreted by bovine adrenocortical cells.
Ouabain is secreted by bovine adrenocortical cells.
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DOI：
10.1210/endo.135.2.8033829
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发表时间：
1994-08
期刊：
影响因子：
4.8
通讯作者：
J. Laredo;B. Hamilton;J. Hamlyn
中科院分区：
文献类型：
--
作者：
J. Laredo;B. Hamilton;J. Hamlyn
哇巴因是钠泵的特异性抑制剂。这种类固醇已在哺乳动物循环中发现大量，可能源自肾上腺。肾上腺细胞分泌哇巴因的研究很少，本工作的目的是确定哇巴因、醛固酮和皮质醇的肾上腺分布，并表征在牛肾上腺皮质细胞原代培养物中 ACTH 和血管紧张素 II 对这些类固醇分泌的影响。在新鲜牛肾上腺中，醛固酮、皮质醇和哇巴因的皮质与髓质比率分别为 14、4.25 和 2.5。在肾上腺皮质细胞原代培养物的条件培养基中检测到所有三种类固醇的含量均升高。分泌型哇巴因免疫反应性的反相 HPLC 显示其与商业哇巴因是等极性的。在存在 10 nM ACTH 或血管紧张素 II 的情况下，所有三种类固醇的分泌在相似的时间过程中均显着增加。哇巴因的刺激分泌超过对照或活化细胞中该类固醇的细胞内含量3-5倍。较大体积培养的细胞中，血管紧张素 II 刺激的哇巴因分泌量更大。这些结果表明哇巴因在牛肾上腺皮质中富集，并由这些细胞的原代培养物分泌。 ACTH 和血管紧张素 II 会增加哇巴因的分泌，这是由于细胞内前体的从头合成或转化所致，该前体不具有明显的免疫反应性，并且受到哇巴因本身或共同分泌因子的反馈调节。这些细胞可能有助于研究刺激-分泌耦合和哇巴因的生物合成途径。
Ouabain is a specific inhibitor of the sodium pump. This steroid has been found in the mammalian circulation in significant amounts and may be of adrenal origin. Secretion of ouabain from adrenal cells has been little studied and the purpose of the present work was to determine the adrenal distribution of ouabain, aldosterone and cortisol, and to characterize the effects of ACTH and angiotensin II on the secretion of these steroids in primary cultures of bovine adrenocortical cells. In fresh bovine adrenals, the cortical to medullary ratios for aldosterone, cortisol and ouabain were 14, 4.25 and 2.5, respectively. All three steroids were detected in elevated amounts in the conditioned medium of primary cultures of adrenocortical cells. Reverse phase HPLC of the secreted ouabain immunoreactivity showed it was isopolar with commercial ouabain. In the presence of 10 nM ACTH or angiotensin II, the secretion of all three steroids increased significantly with similar time courses. The stimulated secretion of ouabain exceeded the intracellular content of this steroid in either control or activated cells by 3-5 fold. The amount of angiotensin II stimulated ouabain secretion was greater from cells incubated in larger volumes. These results show that ouabain is enriched in the bovine adrenal cortex, and is secreted by primary cultures of these cells. The secretion of ouabain is increased by ACTH and angiotensin II, is due to either de novo synthesis or transformation of an intracellular precursor that is not overtly immunoreactive, and is feedback regulated by either ouabain itself or a cosecreted factor. These cells may be useful to study stimulus-secretion coupling and the biosynthetic pathway of ouabain.