Raz E, Kaminski N, Brezis M
Department of Medicine, Hadassah University Hospital, Jerusalem, Israel.
Nephron. 1990;56(4):396-8. doi: 10.1159/000186182.
To explore the effects of renal hemodynamics upon urinary albumin excretion, sequential changes in perfusion pressure and/or flow were performed in isolated perfused rat kidneys. Elevation of perfusion pressure from 90 to 130 mm Hg increased renal flow from 48.9 +/- 1.1 to 54.3 +/- 1.4 ml/min and glomerular filtration rate (GFR) from 0.37 +/- 0.03 to 0.81 +/- 0.06 ml/min (p less than 0.001). Despite more than a doubling in GFR, albumin excretion remained unchanged (from 252 +/- 53 to 167 +/- 36 micrograms/min, p not significant), resulting in a decreased fractional clearance of albumin (theta) from 0.009 +/- 0.002 to 0.004 +/- 0.005 ml/min (p less than 0.01). To dissociate the effects of flow from those of pressure, angiotensin II was infused to decrease renal flow from 49.9 +/- 0.6 to 38.7 +/- 0.6 ml/min (p less than 0.001), while keeping perfusion pressure constant at 96 +/- 1 mm Hg. Although GFR was essentially unchanged (from 0.59 +/- 0.02 to 0.65 +/- 0.05 ml/min, p not significant), albumin excretion increased from 68 +/- 8 to 151 +/- 21 micrograms/min (p less than 0.001) and theta rose from 0.002 +/- 0.000 to 0.005 +/- 0.001 (p less than 0.02). Whole kidney hemodynamics acutely affect renal excretion of albumin in isolated kidneys.
为了探究肾血流动力学对尿白蛋白排泄的影响，在离体灌注大鼠肾脏中依次改变灌注压力和/或血流量。灌注压力从90毫米汞柱升高至130毫米汞柱时，肾血流量从48.9±1.1毫升/分钟增加至54.3±1.4毫升/分钟，肾小球滤过率（GFR）从0.37±0.03毫升/分钟增加至0.81±0.06毫升/分钟（p<0.001）。尽管GFR增加了一倍多，但白蛋白排泄量保持不变（从252±53微克/分钟降至167±36微克/分钟，p无统计学意义），导致白蛋白分数清除率（θ）从0.009±0.002降至0.004±0.005毫升/分钟（p<0.01）。为了区分血流量和压力的影响，输注血管紧张素II使肾血流量从49.9±0.6毫升/分钟降至38.7±0.6毫升/分钟（p<0.001），同时将灌注压力维持在96±1毫米汞柱不变。尽管GFR基本未变（从0.59±0.02毫升/分钟增至0.65±0.05毫升/分钟，p无统计学意义），但白蛋白排泄量从68±8微克/分钟增至151±21微克/分钟（p<0.001），θ从0.002±0.000升至0.005±0.001（p<0.02）。全肾血流动力学可急性影响离体肾脏中白蛋白的肾排泄。
