Distribution of aquaporin 1 in the rat pancreatic duct system examined with light- and election-microscopic immunohistochemistry
Distribution of aquaporin 1 in the rat pancreatic duct system examined with light- and election-microscopic immunohistochemistry
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DOI：
10.1007/s00441-002-0527-x
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发表时间：
2002-04-01
影响因子：
3.6
通讯作者：
Hayakawa, T
中科院分区：
文献类型：
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作者：
Furuya, S;Naruse, S;Hayakawa, T
胰管是胰液分泌的主要部位，但该系统中的水转运途径尚不清楚。最近，水通道蛋白1（AQP 1）的mRNA在离体大鼠小叶间导管检测到强信号。因此，我们进行了光镜和电镜（EM）免疫组化AQP。在大鼠胰管中。在腺泡细胞、腺泡中心细胞和闰管中均未观察到AQP 1免疫反应产物。在直径小于10 μ m的小叶内导管（管腔加导管细胞）中，大多数细胞呈免疫阴性。AQP 1阳性细胞出现在直径为10-15 μ m的小叶内导管中。在直径为15-70 μ m、周围有2-40 μ m厚的管周结缔组织的中小型小叶间导管中，大多数细胞呈不同程度的AQP 1免疫反应阳性。在较大的小叶间导管中，AQP 1的表达是可变的，从免疫阳性到阴性。在主胰管，大多数细胞为阴性的AQP 1。EM免疫组化的小叶内和小叶间导管上皮细胞表明，AQP 1免疫产物更丰富的基底膜比在顶膜，虽然他们都存在于膜。在中等大小的小叶间导管中，AQP 1免疫反应产物沿上皮细胞的顶端、侧突和基底膜沿着密集分布。在不同大小的小叶间导管中，免疫产物不仅与质膜结合，而且与小窝和小泡样结构结合。促胰液素没有诱导任何显着差异，AQP 1的表达和细胞和亚细胞定位。这些结果表明，AQP 1的表达和亚细胞定位的差异很大，这取决于管道的大小，这可能反映了水的运输特性，在不同部门的胰管系统。
The pancreatic duct is the major site for the secretion of pancreatic fluid, but the pathway of water transport in this system is not known. Recently, intense signal for mRNA of aquaporin 1 (AQP1) water channels was detected in isolated rat interlobular ducts. Therefore, we performed light- and electron-microscopic (EM) immunohistochemistry for AQP. in the rat pancreatic ducts. AQP1 immunoproducts ware not observed in the acinar cells, centroacinar cells or intercalated ducts. In the smaller intralobular ducts less than 10 mum in diameter (the lumen plus duct cells), most cells were immunonegative. AQP1-positive cells appeared in intralobular ducts 10-15 mum in diameter. In small and medium-sized interlobular ducts 15-70 mum in diameter surrounded by periductal connective tissue 2-40 mum thick, most cells were AQP1 positive with various degrees of immunoreactivity. In the larger interlobular ducts, the expression of AQP1 was variable, ranging from immunopositive to negative. In the main pancreatic duct, most cells were negative for AQP1. EM immunohistochemistry of the intralobular and small interlobular ductal epithelial cells showed that the AQP1 immunoproducts were more abundant in the basolateral membrane than in the apical membrane, though they were present in both membranes. In the medium-sized interlobular ducts, AQP1 immunoproducts were distributed densely along the apical, lateral interdigitation and basal membrane of the epithelial cells. In the various sizes of interlobular ducts, immunoproducts were associated not only with the plasma membrane, but also with the caveolae and vesicle like structures. Secretin did not induce any significant difference in AQP1 expression and cellular and subcellular localization. These results indicate that the expression and subcellular localization of AQP1 vary considerably depending on the duct size, which may reflect water transport characteristics in the different divisions of the pancreatic duct system.