Nascimento L, Oliveros F H, Cunningham E
Clin Pharmacol Ther. 1984 Mar;35(3):342-7. doi: 10.1038/clpt.1984.41.
The renal handling of Ca in response to Na intake was evaluated in 12 patients with hypercalciuria and active kidney stone disease. There was no depression of urinary Ca excretion in response to the hypocalciuric effect of metolazone. Patients were hospitalized and their Ca and Na excretions measured while on a 190-mEq Na, 800-mg Ca, 1200-mg PO4- diet. These measurements were then repeated after Na intake decreased to 35 mEq/day while other variables, including diuretic dose and Ca intake, were unchanged. Two distinct responses were elicited by patients after Na restriction. In group I or the "responders" (n = 4), Ca excretion was reduced from 255 +/- 31 to 62 +/- 6 mg/24 hr. In the control group (n = 4), Ca excretion decreased from 95 +/- 8 to 57 +/- 11 mg/24 hr at similar levels of Na excretion. In group II or the "nonresponders" (n = 8), Ca excretion fell from 317 +/- 31 to 154 +/- 17 mg/24 hr when Na excretion was less than 50 mEq/24 hr. Metolazone with Na restriction normalized urine Ca excretion to the same order as in control subjects in group I. This is indicative of a mild Ca leak or a salt-sensitive leak. Despite diuretic and Na restriction most of the patients with hypercalciuria (group II) did not reabsorb Ca in a normal manner. This is indicative of a severe reabsorptive defect for Ca despite normal Na handling.
对12例高钙尿症和活动性肾结石病患者进行了评估，以研究肾脏对钠摄入的反应中钙的处理情况。在使用美托拉宗产生低钙尿作用时，尿钙排泄并未降低。患者住院，在摄入190毫当量钠、800毫克钙、1200毫克磷酸盐的饮食时测量其钙和钠排泄量。然后在钠摄入量降至35毫当量/天时重复这些测量，而其他变量，包括利尿剂剂量和钙摄入量，保持不变。钠限制后患者出现两种不同反应。在第一组或“反应者”（n = 4）中，钙排泄量从255±31降至62±6毫克/24小时。在对照组（n = 4）中，在相似的钠排泄水平下，钙排泄量从95±8降至57±11毫克/24小时。在第二组或“无反应者”（n = 8）中，当钠排泄量低于50毫当量/24小时时，钙排泄量从317±31降至154±17毫克/24小时。钠限制联合美托拉宗可使尿钙排泄恢复正常，与第一组对照组受试者相同。这表明存在轻度钙泄漏或盐敏感性泄漏。尽管使用了利尿剂并限制了钠摄入，但大多数高钙尿症患者（第二组）并未以正常方式重吸收钙。这表明尽管钠处理正常，但钙的重吸收存在严重缺陷。
