NACL/FLUID SECRETION BY MAMMALIAN RENAL COLLECTING DUCTS

细胞外液量的维持需要NaCl的摄入和排泄平衡。哺乳动物肾脏中的肾小管和集合管在尿液形成过程中会重新吸收大量的NaCl和液体。然而，一些研究表明，许多管状节段也可能具有净溶质和液体分泌的分子成分。因此，盐和液体的平衡可能是大规模吸收和分泌物微调的结果。内髓收集管（IMCD）的理想位置是在尿液离开肾脏之前对其进行最后的调整。来自IMCD的细胞具有顶端囊性纤维化跨膜传导调节因子（CFTR） Cl通道，并且来自大鼠IMCD细胞的原代培养显示cAMP刺激的电致阴离子分泌。据我所知，氯化钠和体液分泌的人肾单位还没有充分的检查。我将研究人肾小管，特别是肾内小管，在多大程度上可以主动分泌（Na）Cl和液体，从而促进ECV的调节。

The maintenance of the extracellular fluid volume requires a balance NaCl intake and its excretion from the body. It is well established that renal tubules and collecting ducts in the mammalian kidney reabsorb large amounts of NaCl and fluid during urine formation. However, several studies suggest that many tubular segments may also have the molecular components for net solute and fluid secretion. Therefore, it is possible that salt and fluid balance is a consequence of large scale absorption and fine-tuning by secretion. The inner medullary collecting duct (IMCD) is ideally positioned to make the final adjustments to urine before it leaves the kidney. Cells from the IMCD possess apical cystic fibrosis transmembrane conductance regulator (CFTR) Cl channels and primary cultures from rat IMCD cells display electrogenic anion secretion stimulated by cAMP. To my knowledge, NaCl and fluid secretion by the human nephron have not been adequately examined. I will investigate the extent to which human renal tubules, notably the IMCD, can actively secrete (Na)Cl and fluid and thereby contribute to the regulation of ECV.