Smith P R, Bradford A L, Dantzer V, Benos D J, Skadhauge E
Department of Physiology and Biophysics, University of Alabama, Birmingham.
Cell Tissue Res. 1993 Apr;272(1):129-36. doi: 10.1007/BF00323578.
We have used polyclonal antibodies generated against purified bovine renal amiloride-sensitive Na+ channels to localize amiloride-sensitive Na+ channels within the lower intestine (colon and coprodeum) of the hen. These antibodies cross-reacted with two polypeptides exhibiting M(r)'s of 235 and 150 kDa on immunoblots of detergent-solubilized apical membrane fractions from both the colon and coprodeum. The apparent molecular masses of theses polypeptides are in agreement with the M(r)'s of 2 of the subunits of the renal high amiloride-affinity Na+ channel, namely the alpha and the beta (= amiloride binding) subunits. The cellular distribution of Na+ channels was determined by immunoperoxidase and indirect immunofluorescence cytochemical techniques. The apical (luminal) membrane and cytoplasm of villar principal cells in both colon and coprodeum exhibited immunoreactivity, whereas goblet cells were negative. Both principal and goblet cells of the crypts were also negative. We conclude that the amiloride-sensitive Na+ channels are localized to the principal cells of the intestinal villi and that these cells are responsible for intestinal Na+ absorption.
我们利用针对纯化的牛肾氨氯地平敏感钠通道产生的多克隆抗体，来定位鸡下肠道（结肠和粪道）中的氨氯地平敏感钠通道。这些抗体与在结肠和粪道去污剂溶解的顶端膜部分免疫印迹上显示分子量为235和150 kDa的两种多肽发生交叉反应。这些多肽的表观分子量与肾高氨氯地平亲和力钠通道的2个亚基，即α和β（=氨氯地平结合）亚基的分子量一致。通过免疫过氧化物酶和间接免疫荧光细胞化学技术确定钠通道的细胞分布。结肠和粪道绒毛主细胞的顶端（腔）膜和细胞质呈现免疫反应性，而杯状细胞为阴性。隐窝的主细胞和杯状细胞也均为阴性。我们得出结论，氨氯地平敏感钠通道定位于肠绒毛的主细胞，并且这些细胞负责肠道钠吸收。
