Huber S, Asan E, Jöns T, Kerscher C, Püschel B, Drenckhahn D
Institute of Anatomy, Julius-Maximilians-University of Würzburg, 97070 Würzburg, Germany.
Am J Physiol. 1999 Dec;277(6):F841-9. doi: 10.1152/ajprenal.1999.277.6.F841.
By enzyme-linked in situ hybridization (ISH), direct evidence is provided that acid-secreting intercalated cells (type A IC) of both the cortical and medullary collecting ducts of the rat kidney selectively express the mRNA of the kidney splice variant of anion exchanger 1 (kAE1) and no detectable levels of the erythrocyte AE1 (eAE1) mRNA. Using single-cell quantification by microphotometry of ISH enzyme reaction, medullary type A IC were found to contain twofold higher kAE1 mRNA levels compared with cortical type A IC. These differences correspond to the higher intensity of immunostaining in medullary versus cortical type A IC. Chronic changes of acid-base status induced by addition of NH(4)Cl (acidosis) or NaHCO3 (alkalosis) to the drinking water resulted in up to 35% changes of kAE1 mRNA levels in both cortical and medullary type A IC. These experiments provide direct evidence at the cellular level of kAE1 expression in type A IC and show moderate capacity of type A IC to respond to changes of acid-base status by modulation of kAE1 mRNA levels.
通过酶联原位杂交（ISH），提供了直接证据表明，大鼠肾脏皮质和髓质集合管的泌酸闰细胞（A型闰细胞）选择性地表达阴离子交换蛋白1的肾脏剪接变体（kAE1）的mRNA，而未检测到红细胞AE1（eAE1）mRNA的水平。使用ISH酶反应的显微光度法进行单细胞定量分析，发现髓质A型闰细胞中的kAE1 mRNA水平比皮质A型闰细胞高两倍。这些差异与髓质A型闰细胞相对于皮质A型闰细胞更高强度的免疫染色相对应。通过在饮用水中添加NH(4)Cl（酸中毒）或NaHCO3（碱中毒）诱导酸碱状态的慢性变化，导致皮质和髓质A型闰细胞中kAE1 mRNA水平变化高达35%。这些实验在细胞水平上提供了A型闰细胞中kAE1表达的直接证据，并表明A型闰细胞具有通过调节kAE1 mRNA水平来响应酸碱状态变化的适度能力。
