Functional segmentation of the rabbit distal tubule by microdetermination of hormone-dependent adenylate cyclase activity.
Functional segmentation of the rabbit distal tubule by microdetermination of hormone-dependent adenylate cyclase activity.
复制标题
通过微量测定激素依赖性腺苷酸环化酶活性对兔远端小管进行功能分割。
DOI：
10.1038/ki.1976.29
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发表时间：
1976
影响因子：
19.6
通讯作者：
A. Clique
中科院分区：
文献类型：
--
作者：
François Morel;D. Chabardès;Martine Imbert;A. Clique
从胶原酶处理的肾脏显微解剖的兔远曲小管（DCT）在立体显微镜检查下观察到包含多达四个不同外观的部分：（1）DCT a部分（2）恒定的“明亮”部分，DCTb;（3）恒定的“颗粒状”DCTg部分，在大多数DCT中，其连接到具有类似“颗粒状”外观（CCTg）的集合小管的一部分;（4）观察到许多与浅皮质中的肾包膜接触的DCT包含“光”外观的附加部分，DCT 1，类似于这些浅表DCT总是分支到的集合小管（CCT 1）的部分。根据上述标准，通过将显微解剖的远端结构切片成连续样品，并借助先前描述的微量方法，在以下条件之一下测量每个单一样品中所含的酶活性，研究了这些不同部分中所含的腺苷酸依赖性腺苷酸环化酶（AC）：对照，甲状旁腺激素。(PTH 1U/ml）、加压素（AVP 10（-6）M）、异丙肾上腺素（10（-6）M）、氟化物（5 × 10（-3）M）。这些激素分别对以下部分获得了高度显著和可重复的AC刺激：使用PTH的DCTa、DCTg和CCTg;使用AVP的DCTl和CCTl;使用异丙肾上腺素的DCTg、CCTg和CCTl。结论：（a）远曲小管不能再被看作是一个单一的功能结构，（B）DCTa实际上是一个延伸到MD之外的短CAL部分，（c）DCTg和CCT g是同一功能段的两个部分，（d）同样，DCT 1属于主要由CCT 1构成的功能段，（e）DCT 1是一个完整的功能段。最后，（e）DCTb是唯一完全位于远曲小管中的功能片段，即，包括在致密斑和具有另一小管的第一分支之间。
Rabbit distal convoluted tubules (DCT) microdissected from collagenase-treated kidneys were observed to contain up to four portions of a different appearance under stereomicroscopic examination: (1) a DCTa portion (generally very short), located right after the macula densa (MD) and resembling the portion of the limb (CAL) located before the MD; (2) a constant, "bright" portion, DCTb; (3) a constant, "granular" DCTg portion which, in most DCT, is connected to a portion of the collecting tubule of a similar "granular" appearance (CCTg); (4) many DCT having contacts with the kidney capsule in the superficial cortex were observed to contain an additional portion of a "light" appearance, DCTl, resembling the portion of the collecting tubule (CCTl) to which these superficial DCT are always branched. The hormone-dependent adenylate cyclase (AC) contained in these different portions was investigated by sectioning microdissected distal structures into successive samples according to the above-mentioned criteria, and by measuring with the help of a previously described micromethod, the enzyme activity contained in each single sample under one of the following conditions: control, parathyroid hormone. (PTH l U/ml), vasopressin, (AVP 10(-6)M), isoproterenol (10(-6)M), fluoride (5 X 10(-3)M). Highly significant and reproducible AC stimulations by these hormones were obtained for the following portions, respectively: DCTa, DCTg and CCTg with PTH; DCTl and CCTl with AVP; DCTg, CCTg and CCTl with isoproterenol. From these data, it is concluded that (a) the distal convoluted tubule can no longer be regarded as a single well-defined functional structure; (b) DCTa is actually a short CAL portion extending beyond MD, (c) DCTg and CCTg are two portions of a same functional segment; (d) similarly, DCTl belongs to the functional segment mainly constituted by CCTl; and, finally, (e) DCTb is the only functional segment which is entirely located in the distal convoluted tubule, i.e., included between the macula densa and the first branching with another tubule.