Sakai K, Moriya H, Ueyama A, Kishino Y
Department of Nutrition, School of Medicine, University of Tokushima, Japan.
Cell Mol Biol. 1991;37(1):85-94.
When coupled with separation of alveolar macrophages (AM) into four different density fractions (I, II, III and IV) by discontinuous Percoll gradient centrifugation, ultrastructural heterogeneity was evident in secreting process of lysosomal enzymes. Lower dense AM (I and II) released high levels of acid phosphatase and cathepsin B, whereas higher dense ones (III and IV) did not. Ultrastructurally, there were multiple ruffling and active extension of long cytoplasmic processes from one pole or around the cell surface of AM obtained from the higher density fractions. In contrast, AM from lower dense fractions had much less cytoplasmic processes and contained more cytoplasmic vacuoles showing positive reactions of acid phosphatase. These cells featured more frequently round or ovoid knobs with acid phosphatase activity along and from the tips of the cytoplasmic processes, suggestive of exocytosis. It was suggested that these ultrastructural changes linked to the maturation process and release of lysosomal enzymes from differentiated AM.
当通过不连续的Percoll梯度离心将肺泡巨噬细胞（AM）分离成四个不同密度级分（I、II、III和IV）时，溶酶体酶分泌过程中的超微结构异质性很明显。低密度的AM（I和II）释放高水平的酸性磷酸酶和组织蛋白酶B，而高密度的AM（III和IV）则不释放。在超微结构上，从高密度级分获得的AM的一极或细胞表面周围有多个皱褶和长细胞质突起的活跃延伸。相比之下，低密度级分的AM的细胞质突起少得多，并且含有更多显示酸性磷酸酶阳性反应的细胞质空泡。这些细胞更频繁地在细胞质突起的沿线和尖端具有带有酸性磷酸酶活性的圆形或卵形小瘤，提示存在胞吐作用。有人认为，这些超微结构变化与分化的AM中溶酶体酶的成熟过程和释放有关。
