Carbonic anhydrase IV expression in rat and human gastrointestinal tract regional, cellular, and subcellular localization
Carbonic anhydrase IV expression in rat and human gastrointestinal tract regional, cellular, and subcellular localization
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DOI：
10.1172/jci118362
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发表时间：
1995-12-01
影响因子：
15.9
通讯作者：
Sly, WS
中科院分区：
文献类型：
--
作者：
Fleming, RE;Parkkila, S;Sly, WS
碳酸酐酶 IV (CA IV) 是一种糖基磷脂酰肌醇连接的同工酶，先前在肾小管上皮和某些血管内皮细胞表面上发现。该报告确定了 CA IV 在大鼠肠道中的区域、细胞和亚细胞定位。 Northern blot和RT-PCR分析显示CA IV在胃或近端小肠中表达很少，但在远端小肠和大肠中表达丰富，相反，CA II mRNA在胃中丰富，近端小肠减少，远端小肠较低，而在大肠中丰富，CA I mRNA仅在大肠中检测到，CA TV活性的区域分布与CA IV mRNA的分布相关，免疫组化将CA IV定位于远端小肠和大肠的粘膜上皮的顶端质膜。肠，结肠中的信号强度最大，在所有胃肠道区域的粘膜下毛细血管内皮中还发现了 CA IV，人胃和结肠中的免疫组织化学结果与大鼠中的结果相似。这些研究表明，沿着胃肠道的头尾轴，CA 表达具有翻译前同工酶特异性调节。区域、细胞和亚细胞定位与 CA IV 参与远端小肠和大肠中广泛的离子和液体运输一致。
Carbonic anhydrase IV (CA IV) is a glycosylphosphatidyl-inositol-linked isozyme previously identified on the surface of renal tubular epithelium and certain populations of vascular endothelium. This report identifies the regional, cellular, and subcellular localization of CA IV in the rat gut. Northern blot and RT-PCR analyses demonstrated little CA IV expression in stomach or proximal small intestine, but abundant expression in distal small and large intestine, In contrast, CA II mRNA was abundant in stomach, decreased in proximal small intestine, low in distal small intestine, and abundant in large intestine, CA I mRNA was detected only in large intestine, The regional distribution of CA TV activity correlated with distribution of CA IV mRNA, Immunohistochemistry localized CA IV to the apical plasma membrane of the mucosal epithelium in distal small intestine and large intestine, Signal intensity was greatest in colon, CA IV was additionally found in submucosal capillary endothelium of all gastrointestinal regions, Immunohistochemical findings in human stomach and colon paralleled those in the rat, These studies demonstrate pre-translational isozyme-specific regulation of CA expression along the cranial-caudal axis of the gastrointestinal tract, The regional, cellular, and subcellular localizations are consistent with participation of CA IV in the extensive ion and fluid transport in the distal small and large intestine.