Dvorak A M, Hammel I, Schulman E S, Peters S P, MacGlashan D W, Schleimer R P, Newball H H, Pyne K, Dvorak H F, Lichtenstein L M
J Cell Biol. 1984 Nov;99(5):1678-87. doi: 10.1083/jcb.99.5.1678.
We used a morphometric and autoradiographic approach to analyze changes in specific cytoplasmic granules and cytoplasmic lipid bodies associated with human lung mast cell degranulation. Mast cells were dissociated from lung tissue by enzymatic digestion and were then enriched to purities of up to 99% by countercurrent centrifugation elutriation and recovery from columns containing specific antigen bound to Sepharose 6 MB. Degranulation was induced by goat anti-IgE. At various intervals after stimulation, parallel aliquots of cells were recovered for determination of histamine release or were fixed for transmission electron microscopy. We found that lipid bodies, electron-dense structures that lack unit membranes, were present in both control and stimulated mast cells. Autoradiographic analysis showed that lipid bodies represented the major repository of 3H-label derived from [3H]arachidonic acid taken up from the external milieu. By contrast, the specific cytoplasmic granules contained no detectable 3H-label. In addition, lipid bodies occurred in intimate association with degranulation channels during mast cell activation, but the total volume of lipid bodies did not change during the 20 min after stimulation with anti-IgE. This result stands in striking contrast to the behavior of specific cytoplasmic granules, the great majority of which (77% according to aggregate volume) exhibited ultrastructural alterations during the first 20 min of mast cell activation. These observations establish that mast cell cytoplasmic granules and cytoplasmic lipid bodies are distinct organelles that differ in ultrastructure, biochemistry, and behavior during mast cell activation.
我们采用形态测量和放射自显影方法，分析与人类肺肥大细胞脱颗粒相关的特定细胞质颗粒和细胞质脂质体的变化。通过酶消化从肺组织中分离肥大细胞，然后通过逆流离心淘析和从含有与琼脂糖6 MB结合的特异性抗原的柱中回收，将其富集至纯度高达99%。用山羊抗IgE诱导脱颗粒。在刺激后的不同时间间隔，回收平行的细胞等分试样用于测定组胺释放或固定用于透射电子显微镜检查。我们发现脂质体，即缺乏单位膜的电子致密结构，存在于对照和刺激的肥大细胞中。放射自显影分析表明，脂质体是来自外部环境中摄取的[3H]花生四烯酸的3H标记的主要储存库。相比之下，特定的细胞质颗粒未检测到3H标记。此外，在肥大细胞活化期间，脂质体与脱颗粒通道紧密相关，但在用抗IgE刺激后的20分钟内脂质体的总体积没有变化。这一结果与特定细胞质颗粒的行为形成鲜明对比，在肥大细胞活化的最初20分钟内，绝大多数特定细胞质颗粒（根据总体积计算为77%）表现出超微结构改变。这些观察结果表明，肥大细胞细胞质颗粒和细胞质脂质体是不同的细胞器，在肥大细胞活化过程中，它们在超微结构、生物化学和行为方面存在差异。
