Gutmann F D, Rieselbach R E
J Clin Invest. 1971 Feb;50(2):422-31. doi: 10.1172/JCI106509.
Clearance studies were performed on 49 split-bladder dogs with a unilateral pyelonephritic or remnant kidney and three patients with unilateral kidney disease to examine the effects of an acute saline load on the diseased kidney (DK) as opposed to a simultaneously studied, contralateral control kidney (CK), which also served to maintain a nonuremic environment. Before saline loading, base line studies in many of the dogs and the three humans were in agreement with previously published data. However, in dogs with a severe pyelonephritic lesion, a greater difference in DK vs. CK fractional excretion of sodium (FE(Na)) and water was noted, whose magnitude was inversely correlated with the level of glomerular filtration rate (GFR) and maximum urine osmolality of DK compared to CK. An acute saline load (75 ml/kg) resulted in an inhibition of fractional sodium and water reabsorption in the diseased dog kidney which was disproportionately greater than in the simultaneously studied CK, regardless of the type or severity of the lesion. While mean DK GFR for all dogs increased 15% more than CK GFR, failure of FE(Na) to increase after induction of a disproportionate increase in DK GFR with parathyroid hormone suggested that the saline-induced disproportionate increase in GFR was not solely responsible for the exaggerated inhibition of fractional sodium and water reabsorption in the diseased dog kidney. Studies in the three patients after saline loading (25 ml/kg) revealed a similar disproportionate resetting of glomerulotubular balance.Thus, regardless of base line function before expansion, the unilaterally diseased kidney of dog and man possesses unique characteristics in the absence of uremia which render it more reactive to the stimuli produced by acute saline loading. This suggests that the intrarenal environment of the kidney with a reduced nephron population may under some circumstances serve as a determinant of its function.
对49只患有单侧肾盂肾炎或残余肾的分叶膀胱犬以及3例单侧肾病患者进行了清除率研究，以检查急性盐水负荷对患病肾脏（DK）的影响，与之相对的是同时研究的对侧对照肾脏（CK），CK也有助于维持非尿毒症环境。在盐水负荷前，许多犬和这三名人类的基线研究结果与先前发表的数据一致。然而，在患有严重肾盂肾炎病变的犬中，观察到DK与CK的钠分数排泄（FE(Na)）和水的差异更大，其大小与DK相对于CK的肾小球滤过率（GFR）水平和最大尿渗透压呈负相关。急性盐水负荷（75 ml/kg）导致患病犬肾中钠和水的分数重吸收受到抑制，这一比同时研究的CK中受到的抑制大得多，且与病变的类型或严重程度无关。虽然所有犬的平均DK GFR比CK GFR增加了15%以上，但用甲状旁腺激素使DK GFR不成比例增加后FE(Na)未能增加，这表明盐水诱导的GFR不成比例增加并非患病犬肾中钠和水分数重吸收过度抑制的唯一原因。对三名患者进行盐水负荷（25 ml/kg）后的研究显示，肾小球肾小管平衡也有类似的不成比例重置。因此，无论扩容前的基线功能如何，犬和人的单侧患病肾脏在无尿毒症的情况下具有独特特征，使其对急性盐水负荷产生的刺激反应更强。这表明，肾单位数量减少的肾脏的肾内环境在某些情况下可能是其功能的决定因素。
