Na-K-Cl cotransport in the shark rectal gland. I. Regulation in the intact perfused gland.
Na-K-Cl cotransport in the shark rectal gland. I. Regulation in the intact perfused gland.
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鲨鱼直肠腺中的 Na-K-Cl 共转运。
DOI：
10.1152/ajpcell.1992.262.4.c1000
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发表时间：
1992
期刊：
影响因子：
--
通讯作者：
Lytle,C
中科院分区：
文献类型：
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作者：
Forbush3rd,B;Haas,M;Lytle,C
为了研究鲨角鲨（Squalus acanthias）直肠腺中钠-钾-氯共转运系统的调节，我们研究了袢利尿剂[3 H]苯甲他尼与完整腺体的结合。用鲨鱼林格氏溶液灌注腺体，无论是在基础状态还是用血管活性肠肽（VIP）刺激。在灌注的最后25分钟，将[3 H]苯甲他尼加入灌注溶液中，然后将腺体匀浆，并测定膜部分中结合的[3 H]苯甲他尼的量。大多数膜相关的[3 H]-苯甲他尼似乎与钠-钾-氯协同转运蛋白，判断在0 ℃和20 ℃的解离速率，通过标记与光敏类似物，并继续协会的[3 H]苯甲他尼与膜蛋白溶解。随着使用[3 H]4-苯甲酰基-5-氨磺酰基-3-（3- thenyloxy）苯甲酸，苯甲他尼的光敏类似物，200 kDa的蛋白质被选择性地标记暴露于紫外光。还可以在灌注期间检测[3 H]-苯甲他尼结合作为动脉-静脉差异，从而提供结合过程的时间过程。在比较两组5个腺体，VIP刺激NaCl分泌20倍和[3 H]苯甲他尼结合16倍，提供了强有力的证据表明，钠-钾-氯共转运系统被激活的过程中的一部分，刺激分泌。VIP刺激的[3 H]苯甲他尼结合的增加被完全抑制时，Ba被添加到灌注液中，以阻止K通道介导的K出口穿过基底外侧膜。（250字处删节）
To investigate regulation of the Na-K-Cl cotransport system in the rectal gland of the dogfish shark Squalus acanthias, we examined binding of the loop diuretic [3H]benzmetanide to the intact gland. Glands were perfused with a shark Ringer solution, either in a basal state or stimulated with vasoactive intestinal peptide (VIP). [3H]benzmetanide was added to the perfusion solution for the last 25 min of perfusion, after which the gland was homogenized and the amount of bound [3H]benzmetanide was determined in the membrane fraction. Most of the membrane-associated [3H]-benzmetanide appeared to be associated with the Na-K-Cl cotransporter as judged by the dissociation rates at 0 degree C and 20 degrees C, by labeling with a photosensitive analogue, and by continued association of [3H]benzmetanide with membrane protein on solubilization. With the use of [3H]4-benzoyl-5-sulfamoyl-3-(3- thenyloxy)benzoic acid, a photosensitive analogue of benzmetanide, a 200-kDa protein was selectively labeled on exposure to ultraviolet light. It was also possible to detect [3H]-benzmetanide binding during the perfusion period as an arterial-venous difference, thereby providing a time course of the binding process. In comparing two groups of five glands each, VIP stimulated NaCl secretion 20-fold and [3H]benzmetanide binding 16-fold, providing strong evidence that the Na-K-Cl cotransport system is activated as part of the process of stimulation of secretion. The VIP-stimulated increase in [3H]benzmetanide binding was completely inhibited when Ba was added to the perfusate to block K channel-mediated K exit across the basolateral membrane.(ABSTRACT TRUNCATED AT 250 WORDS)