Allison A C, Harington J S, Birbeck M
J Exp Med. 1966 Aug 1;124(2):141-54. doi: 10.1084/jem.124.2.141.
Effects of silica, diamond dust, and carrageenan on mouse macrophages were studied by phase-contrast cine-micrography, electron microscopy, histochemical techniques for lysosomal enzymes and measurements of the release of lysosomal enzymes into the culture medium. All added materials were rapidly taken up into phagosomes, to which lysosomes became attached. In all cases lysosomal enzymes were discharged into the phagosomes to form secondary lysosomes. Within 24 hr most of the silica particles and enzyme had escaped from the secondary lysosomes and lysosomal enzymes were found in the culture media. Most macrophages were killed by this time. With nontoxic particles (diamond dust, aluminium-coated silica, or silica in the presence of the protective agent polyvinyl-pyridine-N-oxide, PVPNO) ingested particles and lysosomal enzymes were retained within the secondary lysosomes for a much longer time, and cytotoxic effects were considerably delayed or absent altogether. It is concluded that silica particles are toxic because they are efficiently taken up by macrophages and can then react relatively rapidly with the membranes surrounding the secondary lysosomes. The particles and lytic enzymes can then escape into the cytoplasm, producing general damage, and thence into the culture medium. It is suggested that hydrogen bonding of silicic acid with lipid and protein constituents of the membrane accounts for the induced permeability. Protective agents such as PVPNO are retamed in lysosomes and preferentially form hydrogen bonds with silicic acid. Carrageenan is demonstrable within macrophages by its metachromatic reaction. It brings about release of enzymes from secondary lysosomes, but much more slowly than does silica. Silica released from killed macrophages is as cytotoxic as the original preparation. It is suggested that repeated cycles of macrophage killing in vivo leads to the mobilization of fibroblasts and fibrogenesis characterizing the disease silicosis.
通过相差电影显微镜、电子显微镜、溶酶体酶组织化学技术以及测量溶酶体酶释放到培养基中的量，研究了二氧化硅、金刚石粉尘和角叉菜胶对小鼠巨噬细胞的影响。所有添加的物质都迅速被吞噬体摄取，溶酶体附着在吞噬体上。在所有情况下，溶酶体酶都被排放到吞噬体中形成次级溶酶体。在24小时内，大部分二氧化硅颗粒和酶从次级溶酶体中逸出，并且在培养基中发现了溶酶体酶。此时大多数巨噬细胞已被杀死。对于无毒颗粒（金刚石粉尘、铝包被的二氧化硅或在保护剂聚乙烯基吡啶-N-氧化物，PVPNO存在下的二氧化硅），摄取的颗粒和溶酶体酶在次级溶酶体内保留的时间要长得多，细胞毒性作用被大大延迟或完全不存在。得出的结论是，二氧化硅颗粒有毒，因为它们被巨噬细胞有效摄取，然后可以相对迅速地与次级溶酶体周围膜发生反应。颗粒和裂解酶随后可以逸出到细胞质中，造成普遍损伤，进而进入培养基。有人认为硅酸与膜的脂质和蛋白质成分的氢键作用导致了诱导的通透性。诸如PVPNO之类的保护剂保留在溶酶体中，并优先与硅酸形成氢键。角叉菜胶通过其异染反应在巨噬细胞内可被证实。它导致酶从次级溶酶体中释放，但比二氧化硅慢得多。从死亡巨噬细胞中释放的二氧化硅与原始制剂一样具有细胞毒性。有人认为，体内巨噬细胞反复被杀死的循环会导致成纤维细胞的动员和纤维化，这是矽肺疾病的特征。
