DeFronzo R A, Taufield P A, Black H, McPhedran P, Cooke C R
Ann Intern Med. 1979 Mar;90(3):310-16. doi: 10.7326/0003-4819-90-3-310.
We examined renal tubular function in six patients with sickle cell hemoglobin. All had normal inulin and para-aminohippurate clearances and impaired urinary concentrating and acidifying abilities. After intravenous potassium chloride administration, maximum excretion of potassium (U,V) was significantly lower in sickle cell patients than in control subjects, and the percentage of potassium load excreted in 5 h was markedly reduced. Urinary potassium excretion after sodium sulfate infusion was also markedly reduced in sickle cell patients compared to control subjects. After 40 mg of oral furosemide, U,V was also diminished in sickle cell patients. Plasma aldosterone response to ACTH and intravenous potassium was similar to that of control subjects. Plasma renin activity increased normally after volume contraction. We conclude that sickle cell patients have a defect in their ability to excrete an acute potassium load that cannot be attributed to abnormal renin or aldosterone secretion. Overall potassium homeostasis is maintained by extrarenal mechanisms during acute potassium loading.
我们研究了6例镰状细胞血红蛋白患者的肾小管功能。所有患者的菊粉和对氨基马尿酸清除率均正常，但尿液浓缩和酸化能力受损。静脉注射氯化钾后，镰状细胞患者的最大钾排泄量（U，V）显著低于对照组，且5小时内排泄的钾负荷百分比明显降低。与对照组相比，镰状细胞患者输注硫酸钠后的尿钾排泄也明显减少。口服40mg速尿后，镰状细胞患者的U，V也降低。血浆醛固酮对促肾上腺皮质激素和静脉注射钾的反应与对照组相似。容量收缩后血浆肾素活性正常增加。我们得出结论，镰状细胞患者排泄急性钾负荷的能力存在缺陷，这不能归因于肾素或醛固酮分泌异常。在急性钾负荷期间，肾脏外机制维持总体钾稳态。
