Cotran R S, Karnovsky M J
J Cell Biol. 1968 Apr;37(1):123-37. doi: 10.1083/jcb.37.1.123.
Peritoneal mesothelium was exposed for 2-60 min to solutions of horseradish peroxidase by incubation in vitro, or after intraperitoneal injection in vivo. Peroxidase was localized, with the electron microscope in the intercellular clefts of the mesothelium, often along their entire lengths, in vesicles adjoining or contiguous with the clefts, and along the peritoneal and basal surfaces of the cell, and also in intracytoplasmic vacuoles. The intercellular junctions of peroxidase-treated mesothelium did not differ from those of controls: open and closed junctions were present in both groups. Intercellular localization was also obtained when the mesothelium was exposed to peroxidase during or after fixation. Although intracellular absorption of peroxidase and its incorporation into larger vacuoles were observed, there was no clearcut evidence of vesicular transport across the mesothelium in these experiments. These findings are consistent with physiologic data which postulate that mesothelial transport can be accounted for, at least in part, by passive diffusion through a system of pores, and they suggest that these pores are located in the intercellular clefts.
通过体外孵育或将辣根过氧化物酶腹腔内注射到体内，使腹膜间皮暴露于辣根过氧化物酶溶液中2至60分钟。用电子显微镜观察到，过氧化物酶位于间皮的细胞间裂隙中，常常沿裂隙全长分布，也存在于与裂隙相邻或连续的小泡中，以及细胞的腹膜表面和基底表面，还存在于胞质内空泡中。经过氧化物酶处理的间皮的细胞间连接与对照组无异：两组均存在开放和闭合连接。当间皮在固定期间或固定后暴露于过氧化物酶时，也能观察到细胞间定位。尽管观察到过氧化物酶的细胞内吸收及其并入较大的空泡中，但在这些实验中没有明确的证据表明有小泡跨间皮转运。这些发现与生理学数据一致，生理学数据推测间皮转运至少部分可通过孔隙系统的被动扩散来解释，并且表明这些孔隙位于细胞间裂隙中。
