Cell specificity of vasopressin binding in renal collecting duct: computer-enhanced imaging of a fluorescent hormone analog.
Cell specificity of vasopressin binding in renal collecting duct: computer-enhanced imaging of a fluorescent hormone analog.
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肾集合管中加压素结合的细胞特异性：荧光激素类似物的计算机增强成像。
DOI：
10.1073/pnas.84.16.6000
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发表时间：
1987
影响因子：
11.1
通讯作者：
Eggena,P
中科院分区：
文献类型：
--
作者：
Kirk,KL;Buku,A;Eggena,P
一种非侵入性的显微镜方法被用来评估细胞特异性的加压素结合内的异质集合管。结合的荧光加压素类似物（1-desamino-8-罗丹明-L-赖氨酸加压素）的细胞的微灌注兔皮质集合小管可视化和定量与图像增强视频显微镜和数字图像处理。在将荧光类似物（10 nM）加入到管周浴中的1-2分钟内，可以检测到与细胞亚群的基底外侧膜的结合。通过加入10倍过量的天然激素可以阻止或逆转结合，这表明荧光类似物特异性结合加压素受体。结合的时间过程中，轻微提前超极化的管腔负跨上皮电压，电反应，也引起的天然激素。双标记实验中，嵌入的细胞群体与荧光素标记的花生凝集素染色显示，加压素类似物的结合定位于其余的细胞类型，主细胞。我们的研究结果支持以下结论。首先，主细胞构成兔皮质集合小管中加压素的主要靶细胞，尽管闰细胞可能具有有限数量的受体，其密度低于这种光学方法的检测限。其次，计算机增强视频显微镜是一种强大的，非侵入性的方法，用于评估激素结合的动力学和空间模式。
A noninvasive microscopic method was used to assess the cell specificity of vasopressin binding within the heterogeneous collecting duct. The binding of a fluorescent vasopressin analog (1-desamino-8-rhodamine-L-lysine vasopressin) to cells of the microperfused rabbit cortical collecting tubule was visualized and quantitated with image-intensified video microscopy and digital image processing. Binding to the basolateral membranes of a subpopulation of cells could be detected within 1-2 min of addition of the fluorescent analog (10 nM) to the peritubular bath. Binding could be prevented or reversed by the addition of a 10-fold excess of the native hormone, which indicates that the fluorescent analog binds specifically to vasopressin receptors. The time course of binding paralleled and slightly preceded hyperpolarization of the lumen-negative transepithelial voltage, an electrical response that is also elicited by the native hormone. Double-label experiments in which the intercalated cell population was stained with fluorescein-labeled peanut lectin revealed that binding of the vasopressin analog was localized to the remaining cell type, the principal cell. Our results support the following conclusions. First, the principal cell constitutes the primary target cell for vasopressin in the rabbit cortical collecting tubule, although the intercalated cell may possess a limited number of receptors at a density below the detection limit of this optical approach. Second, computer-enhanced video microscopy is a powerful, noninvasive method for assessing the kinetics and spatial pattern of hormone binding.