Rodriquez-Soriano J, Vallo A, Castillo G, Oliveros R
Nephron. 1980;25(4):193-8. doi: 10.1159/000181780.
Renal sodium wasting has been observed in both proximal and distal renal tubular acidosis (RTA), although few studies have been reported indicating the tubular localization of such a defect. The use of clearance methodology during hypotonic saline diuresis may give an indirect estimate of proximal tubular reabsorption of sodium, sodium reabsorption at the diluting segments and proportion of sodium load reabsorbed distally. This study was carried out in 17 normal children, in 9 children with proximal RTA, associated in all but one with the Fanconi syndrome, and in 5 children with primary distal RTA. Patients with proximal RTA presented mainly an impaired reabsorption of sodium in the proximal tubule, which was in great part but not completely compensated by an absolute increase in distal sodium reabsorption. Patients with distal RTA showed normal reabsorption of sodium in the proximal tubule but they were unable to reabsorb completely the load of sodium escaping proximal reabsorption due to a defect of sodium reabsorption in the distal diluting segments. These results indicate that the classification of RTA in proximal and distal types is also valid according to the differences found in the tubular handling of water and sodium.
在近端和远端肾小管性酸中毒（RTA）中均观察到肾性失钠，尽管报道的表明这种缺陷的肾小管定位的研究很少。在低渗盐水利尿期间使用清除率方法可能会间接估计近端肾小管对钠的重吸收、稀释段对钠的重吸收以及远端重吸收的钠负荷比例。本研究对17名正常儿童、9名近端RTA儿童（除1名外均伴有范科尼综合征）和5名原发性远端RTA儿童进行。近端RTA患者主要表现为近端小管对钠的重吸收受损，这在很大程度上但并非完全由远端钠重吸收的绝对增加所代偿。远端RTA患者近端小管对钠的重吸收正常，但由于远端稀释段钠重吸收缺陷，他们无法完全重吸收逃脱近端重吸收的钠负荷。这些结果表明，根据在水和钠的肾小管处理中发现的差异，将RTA分为近端型和远端型也是有效的。
