Localization and expression of a collecting duct water channel, aquaporin, in hydrated and dehydrated rats.
Localization and expression of a collecting duct water channel, aquaporin, in hydrated and dehydrated rats.
复制标题
水合和脱水大鼠中集合管水通道、水通道蛋白的定位和表达。
DOI：
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发表时间：
1995
期刊：
影响因子：
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通讯作者：
I. Kihara
中科院分区：
文献类型：
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作者：
T. Yamamoto;S. Sasaki;K. Fushimi;K. Kawasaki;E. Yaoita;K. Oota;Y. Hirata;F. Marumo;I. Kihara
采用免疫组织化学染色、北方印迹分析和放射免疫分析等方法，对水化和脱水大鼠肾脏集合管水通道-水通道蛋白（AQP）-CD的细胞和亚细胞定位和表达进行了研究。在水化大鼠肾脏，AQP-CD选择性地发现在集合管主细胞和内髓集合管细胞，但不是在闰细胞。在光镜水平，AQP-CD弥漫存在于整个集合管细胞的细胞质中的颗粒状图案，并优先积聚在根尖下区域。免疫电镜观察发现，AQP-CD常沿着顶下细胞质小泡膜分布，偶尔沿着这些细胞的基底外侧膜分布。然而，免疫标记是稀疏的顶膜。在脱水大鼠中，AQP-CD免疫染色在集合管细胞的亚顶端细胞质中增强，沿着随着亚顶端区域中AQP-CD承载囊泡的数量和大小的增加以及随着标记沿着顶端膜的增加而增强。脱水大鼠肾脏集合管细胞中AQP-CD含量的增加通过mRNA和蛋白水平AQP-CD的升高来定量证实。AQP-CD定位与集合管中抗利尿激素（ADH）调节的水通道的预测位点一致，脱水导致AQP-CD在mRNA和蛋白水平上的增加可能是脱水受试者尿液浓度高的原因。
The cellular and subcellular localization and expression of a kidney collecting duct water channel, aquaporin (AQP)-CD, were examined in the kidneys of hydrated and dehydrated rats by immunostaining, Northern blot analysis, and radioimmunoassay. In hydrated rat kidneys, AQP-CD was selectively found in the collecting duct principal cells and inner medullary collecting duct cells, but not in the intercalated cells. At a light microscopic level, AQP-CD was diffusely present in a granular pattern throughout the cytoplasm of the collecting duct cells with a preferential accumulation in subapical regions. By immunoelectron microscopy, AQP-CD was frequently demonstrated along membranes of small vesicles in the subapical cytoplasm and occasionally along the basolateral membranes of these cells. However, immunolabeling was sparse on the apical membranes. In dehydrated rats, AQP-CD immunostaining was intensified in the subapical cytoplasm of the collecting duct cells, along with increases in the number and size of AQP-CD-bearing vesicles in the subapical regions and with increment of labeling along the apical membranes. The increase in the amount of AQP-CD in the collecting duct cells of dehydrated rat kidneys was quantitatively confirmed by elevation of AQP-CD at mRNA and protein levels. The AQP-CD localization is consistent with the predicted site of the antidiuretic hormone (ADH)-regulated water channel in the collecting ducts and the increase in AQP-CD at mRNA and protein levels by dehydration may account for high concentration of urine in dehydrated subjects.