Na-K-ATPase localization in teleost urinary bladder by [3H]ouabain autoradiography.
Na-K-ATPase localization in teleost urinary bladder by [3H]ouabain autoradiography.
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通过[3H]哇巴因放射自显影在硬骨鱼膀胱中定位Na-K-ATP酶。
DOI：
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发表时间：
1976
影响因子：
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通讯作者：
W. B. Kinter
中科院分区：
文献类型：
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作者：
J. Renfro;D. Miller;K. Karnaky;W. B. Kinter
以往的研究表明，膀胱的海水驯化的冬比目鱼（pseudopleuronectes americanus）主动钠和氯转运哇巴因敏感。这表明钠泵与Na-K-ATP酶之间存在一定的联系。[H]哇巴因与Na-K-ATP酶的特异性结合提供了一种定位活性Na转运位点的方法。在离体膀胱中，主动钠转运速率与Na-K-ATP酶活性呈线性正相关（r= 0.89）。膀胱表面的哇巴因结合似乎是可饱和的和相对特异的，例如，被高浓度的钾所降低。当仅膀胱粘膜侧暴露于5 μ M哇巴因时，抑制作用和结合都很小，这可以通过膀胱对哇巴因的有限渗透性来解释。相比之下，来自丝氨酸侧的结合和抑制作用要大得多。放射自显影表明，[3 H]哇巴因仅结合到上皮细胞的丝氨酸侧。超微结构检查显示，哇巴因结合区与基底和侧质膜相吻合。
Previous studies on the urinary bladder of the seawater-acclimated winter flounder (pseudopleuronectes americanus) demonstrated that active Na and Cl transport were ouabain sensitive. This suggested a relationship between the Na pump and Na-K-ATP-ase. The specific binding of [H]ouabain to Na-K-ATPase provides a means of localizing the site of active Na transport. In isolated bladders, a positive linear correlation (r= 0.89) was found between the active Na transport rate and the Na-K-ATPase activity. Ouabain binding by the bladder surface appeared to be saturable and relatively specific, e.g., was reduced by a high K concentration. When only the mucosal side of the bladder was exposed to 5 muM ouabain, both inhibitory effects and binding were small and are explained by finite permeability of the bladder to ouabain. In contrast, binding and inhibitory effects from the serosal side were much greater. Autoradiographs demonstrated that [3H]ouabain was bound only to the serosal side of the epithelial cells. Ultrastructural examination revealed that the area of ouabain binding coincided with the basal and lateral plasma membranes.