TURNOVER OF ASYMMETRIC UNIT MEMBRANES IN THE TRANSITIONAL EPITHELIAL SUPERFICIAL CELLS OF THE RAT URINARY-BLADDER
TURNOVER OF ASYMMETRIC UNIT MEMBRANES IN THE TRANSITIONAL EPITHELIAL SUPERFICIAL CELLS OF THE RAT URINARY-BLADDER
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DOI：
10.1002/ar.1092290103
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发表时间：
1991-01-01
影响因子：
--
通讯作者：
YAMAMOTO, TY
中科院分区：
文献类型：
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作者：
AMANO, O;KATAOKA, S;YAMAMOTO, TY
大鼠移行上皮表层细胞的管腔表面、梭形小泡和多囊泡体上可见不对称的厚单位膜。将辣根过氧化物酶标记的蓖麻凝集素(RCA-I)注入大鼠膀胱后，RCA-I沿管腔细胞膜和某些多囊泡体沉积，但在收缩前后的梭形小泡内均无沉积。用Vibratome切开膀胱，固定后用HRP标记的RCA-I染色，发现RCA-I存在于许多细胞器中，包括梭形小泡、多囊泡体以及管腔表面。用HRP标记的RCA-I对小块组织进行整体染色时，RCA-I沿管腔细胞表面可见，但在梭形小泡和多泡小体中未见。将HRP单独注入膀胱时，在收缩后的部分多囊泡内可观察到HRP，而在梭形小泡内未见HRP。电子显微镜下可观察到多种溶酶体。有的呈环状包裹多囊泡体，有的含有不对称的单位膜。这些发现表明，不对称的单位膜通过纺锤形小泡运输到管腔细胞膜，旧的管腔细胞膜通过多囊泡体被去除，被溶酶体降解。
Asymmetric thick unit membranes were observed on the luminal surface, fusiform vesicles, and multivesicular bodies of superficial cells of rat transitional epithelium. When HRP‐labeledRicinus communislectin (RCA‐I) was injected into the rat urinary bladder, RCA‐I was deposited along the luminal cell membrane and in some multivesicular bodies, but not in the fusiform vesicles either before or after contraction. When the bladder was sliced by Vibratome and stained with HRP‐labeled RCA‐I after fixation, RCA‐I was observed in many cell organelles, including fusiform vesicles and multivesicular bodies as well as the luminal surface. When small pieces of tissue were stained en‐bloc with HRP‐labeled RCA‐I, RCA‐I was found along the luminal cell surface but not in the fusiform vesicles nor the multivesicular bodies. When HRP alone was injected into the bladder, HRP was observed in some multivesicular bodies after contraction but not in the fusiform vesicles. Various lysosomes were observed by electron microscopy. Some were wrapping multivesicular bodies in ringlike fashion, and some contained asymmetric unit membranes. These findings suggest that the asymmetric unit membranes are carried to the luminal cell membrane via the fusiform vesicles and that old luminal cell membranes are removed via the multivesicular bodies to be degraded by lysosomes.