Cells and intercellular contacts in glomeruli and tubules of the frog kidney
Cells and intercellular contacts in glomeruli and tubules of the frog kidney
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青蛙肾肾小球和肾小管的细胞和细胞间接触
DOI：
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发表时间：
2004
影响因子：
3.6
通讯作者：
S. Ntokalou
中科院分区：
文献类型：
--
作者：
R. Taugner;A. Schiller;S. Ntokalou
摘要通过使用薄片和冷冻断裂复制品，研究了青蛙（Rana esculenta）肾脏的肾小球和管状结构，特别是细胞间连接。在肾小球中，过滤屏障的厚度变化很大，足细胞突起之间经常发生紧密和间隙连接接触。尽管结构上不太复杂，但近端小管与哺乳动物的近端小管相似。在初始部分，紧密连接相对较浅，但在近端小管的中部和远端部分变得非常宽。近端肾小管细胞通过间隙连接广泛连接。在一些动物中，近端小管的近端和远端部分的细胞形状明显不同。远端小管由两段组成，主要区别在于交叉的模式和闭塞小带的结构。与哺乳动物远端小管的紧密连接形态有惊人的相似之处。在远端小管的第一部分（稀释段）中，发现了一条平行紧密连接的窄带，与哺乳动物直远端小管中的连接非常相似。然而，在远端小管的更远端部分，存在宽阔的吻合紧密连接链，就像哺乳动物回旋远端小管的闭锁带一样。连接小管表现出细胞二态性：其壁包含浅色和深色（烧瓶）细胞的混合物。烧瓶细胞的腔膜和基底外侧膜覆盖有许多杆状颗粒。连接管的紧密连接很宽，并且沿着其长度深度和股线数量增加；尽管与系统发育上较年轻的肾脏存在一些差异，但我们的研究结果表明，哺乳动物肾脏的许多结构原理也体现在两栖动物的肾脏中。讨论了结构-功能关系。
SummaryBy the use of thin sections and freeze-fracture replicas the glomerular and tubular structures of the kidney of the frog (Rana esculenta) were studied with special reference to intercellular junctions.In the glomerulus the filtration barrier is of very variable thickness, and frequent tight and gap junctional contacts occur between podocyte processes.Although structurally less elaborate, the proximal tubule resembles its mammalian counterpart. In the initial part the tight junctions are relatively shallow but become very broad in the mid and distal portions of the proximal tubule. The proximal tubular cells are extensively linked by gap junctions. In some animals the shapes of the cells in the proximal and distal portions of the proximal tubule were markedly different.The distal tubule consists of two segments which differ mainly in the pattern of interdigitations and the structure of the zonulae occludentes. Similarities with the tight junctional morphology of the mammalian distal tubule are striking. In the first part of the distal tubule (diluting segment) a narrow band of parallel tight junctions is found closely resembling that found in the mammalian straight distal tubule; in the more distal part of the distal tubule, however, a broad band of anastomosing tight junctional strands exists, like the zonula occludens of the mammalian convoluted distal tubule.The connecting tubule displays cellular dimorphism: its wall contains a mixture of light and dark (flask) cells. The luminal and basolateral membranes of the flask cells are covered with numerous rod-shaped particles. The tight junctions of the connecting tubule are broad and increase in depth and number of strands along its length; they are typical of a very tight epithelium.In spite of several dissimilarities with phylogenetically younger kidneys our findings suggest that many structural principles of the mammalian kidney are also represented in the kidneys of amphibians. The structural-functional relationships are discussed.
肾小管转运机制。
影响因子：
3.3
作者：
Ausiello,DA
通讯作者：
Ausiello,DA