Electron-microscopic study of the apical region of the toad bladder epithelial cell.
Electron-microscopic study of the apical region of the toad bladder epithelial cell.
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蟾蜍膀胱上皮细胞顶端区域的电子显微镜研究。
DOI：
10.1152/ajpcell.1984.247.3.c268
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发表时间：
1984
期刊：
影响因子：
--
通讯作者：
Hays,RM
中科院分区：
文献类型：
--
作者：
Sasaki,J;Tilles,S;Condeelis,J;Carboni,J;Meiteles,L;Franki,N;Bolon,R;Robertson,C;Hays,RM
抗利尿激素（ADH）促进细胞质小管与管腔膜的融合，并将颗粒从小管递送到膜。这些颗粒被认为是膜中的导水元素。本文应用扫描电镜（SEM）和透射电镜（TEM）技术研究了蟾蜍膀胱上皮细胞胞质小管与腔膜和顶端细胞骨架的关系。本文报道了冷冻裂纹扫描电镜和单宁酸固定透射电镜的研究结果，以及与无树脂包埋方法的研究。冷冻裂解的上皮细胞显示，小管锚定在细胞骨架和颗粒的基质中，就在腔膜下方，并且许多（如果不是全部）在ADH诱导的融合后保留其锚定到基质。单宁酸固定的标本显示未受刺激的细胞中的小管水平排列。融合似乎涉及的角度的小管，这可能是ADH诱导的小管运动的主要模式。鞣酸切片显示小管与周围细胞骨架的丝状连接。此外，有突出的微丝束沿着微绒毛向下延伸，并且在腔膜下方有密集的微丝。这些细丝的存在下，证实了在无树脂的部分，并讨论了它们在ADH行动中可能发挥的作用。
Antidiuretic hormone (ADH) promotes fusion of cytoplasmic tubules with the luminal membrane and delivery of particles from the tubules to the membrane. The particles are believed to be the water-conducting elements in the membrane. We have employed several scanning (SEM) and transmission electron-microscopic (TEM) techniques to study the relationship of the cytoplasmic tubules to the luminal membrane and to the apical cytoskeleton of the toad bladder epithelial cell. This paper reports the results of freeze-crack SEM and tannic acid-fixed TEM studies, as well as studies with a resinless method of embedding. Freeze-cracked epithelial cells reveal that the tubules are anchored in a matrix of cytoskeleton and granules just below the luminal membrane, and many, if not all, retain their anchorage to the matrix after ADH-induced fusion. Tannic acid-fixed specimens show that the tubules in unstimulated cells lie horizontally. Fusion appears to involve an angulation of the tubules, and this may be the major mode of ADH-induced tubule movement. There are suggestions in the tannic acid sections of filamentous attachments of tubules to the surrounding cytoskeleton. In addition there are prominent microfilament bundles running down the microvilli and a dense concentration of filaments just below the luminal membrane. The presence of these filaments is confirmed in the resinless sections, and their possible role in ADH action is discussed.