Muller J, Kachadorian W A
Am J Physiol. 1984 Jul;247(1 Pt 1):C90-8. doi: 10.1152/ajpcell.1984.247.1.C90.
Aggregates of intramembrane particles are found in cytoplasmic structures that we now term "aggrephores." Antidiuretic hormone (ADH) causes aggrephores to fuse with the luminal membrane. Aggregates subsequently become dispersed in the membrane and behave as sites for water flow. In the present studies we examined further the behavior of aggrephores. 1) Bladders stimulated for 10, 30, or 60 min in the absence of an osmotic gradient had two to three times more fusions as those stimulated in the presence of a gradient, indicating that aggrephore fusion frequency is influenced by water flow. 2) ADH stimulation did not change the projected luminal surface area of granular cells. Thus fused aggrephores remain fixed while aggregates move from the aggrephore to flat areas of luminal membrane. 3) Horseradish peroxidase, present in the mucosal baths of bladders stimulated with and then washed of ADH, was found in the lumen of cytoplasmic aggrephores; aggrephores therefore detach from the luminal membrane during washout. The same bladders had about twice as many multivesicular body-type lysosomes as unstimulated bladders, suggesting that, after detachment, aggrephores may join or become lysosomes. 4) Colchicine did not affect the rate of disappearance of fusion sites during washout, whereas cytochalasin B slowed it, suggesting that aggrephore detachment depends of microfilaments, but not microtubules.
在我们现在称为“聚集体载体”的细胞质结构中发现了膜内颗粒聚集体。抗利尿激素（ADH）使聚集体载体与管腔膜融合。随后聚集体分散在膜中并作为水流的位点。在本研究中，我们进一步研究了聚集体载体的行为。1）在没有渗透梯度的情况下刺激10、30或60分钟的膀胱，其融合次数是在有梯度存在时刺激的膀胱的两到三倍，这表明聚集体载体融合频率受水流影响。2）ADH刺激并未改变颗粒细胞的预计管腔表面积。因此，融合的聚集体载体保持固定，而聚集体从聚集体载体移动到管腔膜的平坦区域。3）在用ADH刺激然后冲洗的膀胱的黏膜浴中存在的辣根过氧化物酶，在细胞质聚集体载体的管腔中被发现；因此，在冲洗过程中聚集体载体从管腔膜脱离。相同的膀胱中多囊泡体类型的溶酶体数量大约是未刺激膀胱的两倍，这表明在脱离后，聚集体载体可能会合并或变成溶酶体。4）秋水仙碱不影响冲洗过程中融合位点消失的速率，而细胞松弛素B会使其减慢，这表明聚集体载体的脱离依赖于微丝，而不是微管。
