Brøchner-Mortensen J, Støckel M, Sørensen P J, Nielsen A H, Ditzel J
Diabetologia. 1984 Aug;27(2):189-92. doi: 10.1007/BF00273804.
To evaluate the glomerulo-tubular balance of sodium and water in the proximal tubules of diabetic patients with elevated glomerular filtration rate, the renal plasma clearance of lithium and the glomerular filtration rate (51Cr-EDTA plasma clearance) were determined simultaneously in 11 ambulatory Type 1 (insulin-dependent) diabetic patients (aged 25-35 years) with no evidence of diabetic nephropathy and in 10 age-matched healthy subjects. The renal plasma clearance of lithium, which is a measure of flow from the proximal tubule into the thin descending limb of the loop of Henle, did not differ between diabetic and control subjects (28.9 +/- 4.0 versus 28.3 +/- 5.1 ml/min per 1.73 m2 surface area, mean +/- SD), whereas the glomerular filtration rate in the diabetic patients was significantly higher than in the control subjects (136 +/- 10.2 versus 108 +/- 13.6 ml/min per 1.73 m2, p less than 0.001). The same held true for the fractional reabsorption rate in the proximal tubules (78.7 +/- 3.2 versus 73.6 +/- 4.9%, p less than 0.02). The results indicate that the elevation of the glomerular filtration rate in diabetic patients is associated with a parallel increase in the proximal reabsorption rate. This type of glomerulo-tubular balance implies that the flow of water and flux of sodium to the segments distal to the proximal tubule are kept constant during variations in the glomerular filtration rate.
为评估肾小球滤过率升高的糖尿病患者近端小管中钠和水的球管平衡，我们对11例无糖尿病肾病证据的门诊1型（胰岛素依赖型）糖尿病患者（年龄25 - 35岁）和10例年龄匹配的健康受试者同时测定了锂的肾血浆清除率和肾小球滤过率（51Cr - EDTA血浆清除率）。锂的肾血浆清除率可衡量从近端小管到髓袢细降支的流量，糖尿病患者与对照组之间无差异（每1.73 m2体表面积分别为28.9±4.0和28.3±5.1 ml/min，均值±标准差），而糖尿病患者的肾小球滤过率显著高于对照组（每1.73 m2分别为136±10.2和108±13.6 ml/min，p<0.001）。近端小管的分数重吸收率情况相同（分别为78.7±3.2和73.6±4.9%，p<0.02）。结果表明，糖尿病患者肾小球滤过率的升高与近端重吸收率的平行增加相关。这种类型的球管平衡意味着在肾小球滤过率变化期间，水的流量和钠向近端小管远端节段的通量保持恒定。
