Rabelink A J, Koomans H A, Boer W H, Dorhout Mees E J, van Rijn H J
Department of Nephrology and Hypertension, University Hospital Utrecht, The Netherlands.
Nephrol Dial Transplant. 1989;4(1):27-31.
We examined the effect of semi-acute indomethacin (4 x 50 mg orally during the preceding 27 h) on renal function parameters, including fractional lithium reabsorption (FRLi) in seven healthy subjects during a 200 mmol and a 40 mmol sodium diet. Studies were carried out during maximal water diuresis. During the sodium-rich diet, indomethacin raised minimal urine osmolality from 61 +/- 1 to 72 +/- 2 mosm/kg (P less than 0.05), and during the sodium-restricted diet from 55 +/- 3 to 93 +/- 6 mosm/kg (P less than 0.01). Indomethacin reduced maximal free water clearance only during the low-sodium diet, and had no consistent effect on inulin clearance and the fractional excretions of sodium, phosphate and uric acid. Nevertheless, FRLi rose substantially, from 71 +/- 2% to 75 +/- 2% (P less than 0.01) and from 75 +/- 2% to 81 +/- 2% (P less than 0.01) during high- and low-sodium diets respectively. During either diet, indomethacin caused a significant reduction of 24-h urine PGE2 excretion. Since indomethacin is not supposed to influence proximal tubular sodium reabsorption, the rise in lithium reabsorption occurred beyond this nephron level, presumably in the loop of Henle. Clearly, the FRLi cannot be used as a quantitative marker of proximal tubular sodium reabsorption in humans in all conditions.
我们研究了半急性吲哚美辛（在前27小时内口服4次，每次50毫克）对7名健康受试者在200毫摩尔和40毫摩尔钠饮食期间肾功能参数的影响，包括锂的分数重吸收（FRLi）。研究在最大水利尿期间进行。在高钠饮食期间，吲哚美辛使最低尿渗透压从61±1毫渗量/千克升高至72±2毫渗量/千克（P<0.05），在低钠饮食期间从55±3毫渗量/千克升高至93±6毫渗量/千克（P<0.01）。吲哚美辛仅在低钠饮食期间降低了最大自由水清除率，对菊粉清除率以及钠、磷酸盐和尿酸的分数排泄没有一致的影响。然而，在高钠和低钠饮食期间，FRLi分别从71±2%大幅升至75±2%（P<0.01）和从75±2%升至81±2%（P<0.01）。在任何一种饮食期间，吲哚美辛均导致24小时尿PGE2排泄显著减少。由于吲哚美辛不应影响近端小管钠重吸收，锂重吸收的增加发生在该肾单位水平之外，可能在髓袢。显然，在所有情况下，FRLi都不能用作人类近端小管钠重吸收的定量标志物。
