肺胞毛細血管上皮, 肺胞上皮における閉鎖帯の微細構造, ならびにANTUによる変化について

ラット肺のフリーズレプリカ法による検討

抄録

Zonulae occludentes in the alveolar epithelium and pulmonary capillary endothelium of the rat lung were studied electron-microscopically using the freeze fracture technique. The effect of alphanaphthylthiourea (ANTU) was also studied in rats which were sacrificed 30 to 60 minutes after intraperitoneal administration of ANTU. Zonulae occludentes between endothelial cells formed belts (0.04 to 0.2μ in width) with loose networks which were made of lines of particles (80 to 100Å in diameter) in the cytoplasmic membranes. On the other hand, those in the epithelium showed wider belts and finer networks in which continuous line structures formed fibrils with about 100Å in thickness. It was often observed that two running fibrils connected together and formed a single thicker fibril. Almost all particles in endothelium disappeared shortly after the administration of ANTU even when no edematous change nor alterations in intercellular junctions were detected by the observation of the ultrathin sections. Morphological and functional differences of zonulae occludentes between the epithelium and the endothelium were discussed.