内淋巴囊内淋巴的内吞作用和跨上皮转运。

Endocytosis and transepithelial transport of endolymph in the endolymphatic sac.

作者信息

Fukazawa K, Sakagami M, Umemoto M, Kubo T

机构信息

Department of Otolaryngology, Kinki Central Hospital, Hyogo, Japan.

出版信息

Hear Res. 1995 Jun;86(1-2):82-8. doi: 10.1016/0378-5955(95)00058-c.

DOI:10.1016/0378-5955(95)00058-c

PMID:8567425

Abstract

The fate of cationized ferritin (CF) injected into the endolymphatic space of the endolymphatic sac was observed by transmission electron microscopy. At 10 min after the injection, CF particles bound to the apical plasma membrane of epithelial cells of the sac and were then endocytosed with coated pits. However, they never passed through the junctional complexes between the epithelial cells. At 30 min after the injection, the CF particles were transferred to endosomes and lysosomes by small vesicles of 100-150 nm in diameter. CF particles were also found in small vesicles close to Golgi cisternae and in multivesicular bodies. Acid phosphatase positive lysosomes were found close to endosomes containing CF particles. In addition, a small fraction of the small vesicles containing CF particles became inserted into the basolateral plasma membrane. At 60 min after the injection, many CF particles were found in acid phosphatase positive secondary lysosomes. These observations suggest that endocytosis of endolymph is actively performed by the epithelial cells of the sac, and transepithelial vesicular transport across the epithelial cells occurs.

摘要

通过透射电子显微镜观察注入内淋巴囊内淋巴间隙的阳离子铁蛋白（CF）的命运。注射后10分钟，CF颗粒结合到囊上皮细胞的顶端质膜上，然后通过有被小窝被内吞。然而，它们从未穿过上皮细胞之间的连接复合体。注射后30分钟，CF颗粒通过直径为100 - 150 nm的小囊泡转移到内体和溶酶体中。在靠近高尔基池的小囊泡和多泡体中也发现了CF颗粒。在含有CF颗粒的内体附近发现了酸性磷酸酶阳性的溶酶体。此外，一小部分含有CF颗粒的小囊泡插入到基底外侧质膜中。注射后60分钟，在酸性磷酸酶阳性的次级溶酶体中发现了许多CF颗粒。这些观察结果表明，囊的上皮细胞积极进行内淋巴的内吞作用，并且发生了跨上皮细胞的囊泡转运。