Laduron P, Aerts G, De Bie K, Van Gompel P
Department of Neurobiochemistry, Janssen Pharmaceutica, B-2340 Beerse, Belgium.
Neuroscience. 1976 Jun;1(3):219-26. doi: 10.1016/0306-4522(76)90080-4.
Tissue fractionation was used as an analytical tool to study the subcellular distribution of an adenosine triphosphatase activated by Mg2+ in adrenal medullae of the pig and ox and in whole adrenals of the rat. By measuring adenosine triphosphatase and various enzymes in the fractions obtained by differential centrifugation, the distribution pattern of adenosine triphosphatase was found to differ markedly from that of markers like catecholamines, dopamine beta-hydroxylase or cytochrome oxidase. In the pig and ox the distribution of inosine diphosphatase paralleled that of adenosine triphosphatase. After equilibration through sucrose density gradients, no adenosine triphosphatase activity was detected in the chromaffin granules in the rat. However, in bovine adrenal medullae, a large part of the adenosine triphosphatase activity equilibrated in that area of the gradient in which the chromaffin granules were found. This adenosine triphosphatase distribution pattern was an artefact produced by applying a too concentrated sample to the gradient. When a more diluted sample of bovine tissue was used no adenosine triphosphatase activity was found to be associated with the chromaffin granules. The present results lead to a reconsideration of the role of the adenosine triphosphatase in some processes in which the chromaffin granules are involved. Moreover, the degree of purity of many chromaffin granule preparations is again questioned.
组织分级分离被用作一种分析工具，以研究猪和牛肾上腺髓质以及大鼠整个肾上腺中由Mg2+激活的三磷酸腺苷酶的亚细胞分布。通过测量差速离心得到的各组分中的三磷酸腺苷酶和各种酶，发现三磷酸腺苷酶的分布模式与儿茶酚胺、多巴胺β-羟化酶或细胞色素氧化酶等标志物的分布模式明显不同。在猪和牛中，肌苷二磷酸酶的分布与三磷酸腺苷酶的分布平行。通过蔗糖密度梯度平衡后，在大鼠的嗜铬颗粒中未检测到三磷酸腺苷酶活性。然而，在牛肾上腺髓质中，大部分三磷酸腺苷酶活性在梯度中发现嗜铬颗粒的区域达到平衡。这种三磷酸腺苷酶的分布模式是由于向梯度中加入了过于浓缩的样品而产生的假象。当使用更稀释的牛组织样品时，未发现三磷酸腺苷酶活性与嗜铬颗粒相关。目前的结果导致重新考虑三磷酸腺苷酶在嗜铬颗粒参与的某些过程中的作用。此外，许多嗜铬颗粒制剂的纯度再次受到质疑。
