Konings F, Majchrowicz B, De Potter W
Am J Physiol. 1983 May;244(5):C309-12. doi: 10.1152/ajpcell.1983.244.5.C309.
Cell-free interaction between bovine adrenal medullary plasma membranes and chromaffin granules results in the release of the granular content, a process specifically controlled by micromolar concentrations of calcium and therefore regarded as a putative model for exocytosis. The density gradient distribution of interacted organelles (1 min at 37 degrees C) was compared with the distribution of noninteracted material (kept at 0 degree C). Self-generating Percoll gradients, in which intact chromaffin granules were separated from plasma membranes and empty granule "ghosts," were used. The plasma membrane-induced release of the chromaffin granular matrix upon concomitant incubation was demonstrated by the disappearance of the "intact granule" peak accompanied by a proportional rise of the "granule ghost" peak. The degree of granule disappearance depended on the amount of plasma membranes added. The soluble content of the fraction that had disappeared was dispersed throughout the gradient. No shift of the granule peak toward intermediate densities was observed; this suggests that the loss of each granule's content is an all-or-none phenomenon rather than a partial release.
牛肾上腺髓质质膜与嗜铬颗粒之间的无细胞相互作用导致颗粒内容物的释放，这一过程由微摩尔浓度的钙特异性控制，因此被视为胞吐作用的一种假定模型。将相互作用的细胞器（在37℃下1分钟）的密度梯度分布与未相互作用的物质（保存在0℃）的分布进行比较。使用自生成的Percoll梯度，其中完整的嗜铬颗粒与质膜和空颗粒“幽灵”分离。伴随孵育时质膜诱导的嗜铬颗粒基质释放通过“完整颗粒”峰的消失以及“颗粒幽灵”峰的相应升高得以证明。颗粒消失的程度取决于添加的质膜量。已消失部分的可溶性内容物分散在整个梯度中。未观察到颗粒峰向中间密度的移动；这表明每个颗粒内容物的损失是一种全或无的现象，而非部分释放。
