Activation of acid-secreting intercalated cells in rabbit collecting duct with ammonium chloride loading.
Activation of acid-secreting intercalated cells in rabbit collecting duct with ammonium chloride loading.
复制标题
用氯化铵负载激活兔集合管中的泌酸嵌入细胞。
DOI：
10.1152/ajprenal.1994.266.4.f633
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发表时间：
1994
期刊：
影响因子：
--
通讯作者：
Tisher,CC
中科院分区：
文献类型：
--
作者：
Verlander,JW;Madsen,KM;Cannon,JK;Tisher,CC
正常家兔外髓集管（OMCD）插层细胞免疫标记显示基底外侧质膜中有3-带状蛋白（15），顶质膜和细胞质囊泡中有H(+)-腺苷三磷酸酶（H(+)- atp酶）（30）。然而，在皮质集管（CCD）的A型插层细胞中，3-样带蛋白主要位于多泡体和细胞质泡中（15），而H(+)- atp酶仅在大多数插层细胞中存在于细胞质泡中（30）。在这项研究中，我们观察了慢性酸负荷对集管中这些转运蛋白免疫定位的影响。成年新西兰大白兔分别饮用正常自来水（对照组）或75 mM NH4Cl，连续12天，每天8次灌胃，剂量为2-6 meq NH4Cl/kg体重。死亡时，酸负荷动物的平均尿液pH为5.96 (SD = 0.69)，对照组为8.47 （SD = 0.07）。采用活体灌注固定肾脏，进行3带样蛋白免疫过氧化物酶定位和H(+)- atp酶免疫金定位的光镜和电镜处理。在对照组中，带3样蛋白主要局限于CCD中大多数阳性染色插层细胞的多泡体，以及OMCD中插层细胞的基底外侧质膜。在酸负荷家兔中，带3蛋白阳性嵌入细胞在内层CCD和外层OMCDo呈明显的星状。基底外侧质膜标记增强，标记的多泡体数量减少。形态计量学分析表明，这些插层细胞的基底外侧质膜数量增加。在对照家兔中，CCD插层细胞的H(+)- atp酶免疫反应性主要位于细胞质囊泡上方。少数嵌入细胞显示基底外侧质膜标记，只有少数细胞显示顶端质膜标记。在负酸家兔中，H(+)- atp酶免疫反应性沿内CCD插层细胞的顶质膜增强，形态计量学分析表明，这段带3阳性插层细胞的顶质膜增加。这些结果表明，家兔对酸负荷的反应是通过增强CCD和OMCDo内部嵌入细胞的电致质子分泌和Cl-/HCO3-交换来实现的。
In normal rabbit, immunolabeling of intercalated cells in the outer medullary collecting duct (OMCD) demonstrates band 3-like protein in the basolateral plasma membrane (15) and H(+)-adenosinetriphosphatase (H(+)-ATPase) in the apical plasma membrane and cytoplasmic vesicles (30). However, in type A intercalated cells in the cortical collecting duct (CCD), band 3-like protein is located primarily in multivesicular bodies and cytoplasmic vesicles (15), whereas H(+)-ATPase is present in cytoplasmic vesicles only in most intercalated cells (30). In this study, we observed the effect of chronic acid loading on immunolocalization of these transporters in the collecting duct. Adult New Zealand White rabbits received either normal tap water (controls) or 75 mM NH4Cl for 12 days plus eight daily gavages of 2-6 meq NH4Cl/kg body wt. At time of death, mean urine pH of acid-loaded animals was 5.96 (SD = 0.69), vs. 8.47 (SD = 0.07) in controls. Kidneys were fixed by in vivo perfusion and processed for light and electron microscopic immunoperoxidase localization of band 3-like protein and immunogold localization of H(+)-ATPase. In controls, band 3-like protein was largely confined to multivesicular bodies in the majority of positive-staining intercalated cells in the CCD and to the basolateral plasma membrane of intercalated cells in the OMCD. In acid-loaded rabbits, band 3 protein-positive intercalated cells in the inner CCD and the in the outer stripe of the OMCD (OMCDo) were strikingly stellate in form. Basolateral plasma membrane label was intensified, while the number of labeled multivesicular bodies was diminished. Morphometric analysis demonstrated an increase in the amount of basolateral plasma membrane in these intercalated cells. In control rabbits, H(+)-ATPase immunoreactivity in intercalated cells in the CCD was located predominantly over cytoplasmic vesicles. A minority of intercalated cells exhibited basolateral plasma membrane label, and only an occasional cell displayed apical plasma membrane label. In acid-loaded rabbits, H(+)-ATPase immunoreactivity was enhanced along the apical plasma membrane of intercalated cells in the inner CCD, and morphometric analysis demonstrated increased apical plasma membrane in band 3-positive intercalated cells in this segment. These results suggest that rabbits respond to acid loading via enhancement of both electrogenic proton secretion and Cl-/HCO3- exchange in intercalated cells in the inner CCD and the OMCDo.