Cho J, Galaske R G, Arbesman H, Van Liew J B
Ren Physiol. 1985;8(1):8-18. doi: 10.1159/000173029.
The normal filtered load of albumin at the rat glomerulus was estimated to be 18 mg/24 h X g kidney weight by means of micropuncture studies. Total nephron fractional reabsorption was 91%. The proximal convoluted tubule accounted for 72% of total reabsorption followed by an additional 12% in the loop of Henle. Only minimal protein uptake occurred in more distal parts of the nephron. Na maleate, given at a dosage of 2 mM/kg body weight 2 h prior to micropuncture, inhibited tubular albumin uptake in the proximal convoluted tubule. As in controls there was no measurable protein uptake beyond the loop of Henle. These results indicated that tubular reabsorption of albumin was virtually completed by the early distal convoluted tubule. Maleate was found to be a potent inhibitor of protein transport in the proximal convoluted tubule resulting in a fractional excretion of albumin of 50%.
通过微穿刺研究估计，大鼠肾小球白蛋白的正常滤过量为每24小时18毫克/克肾脏重量。总肾单位分数重吸收率为91%。近曲小管占总重吸收的72%，其次是髓袢额外重吸收12%。在肾单位更远端部分仅发生极少的蛋白质摄取。在微穿刺前2小时，以2毫摩尔/千克体重的剂量给予马来酸钠，可抑制近曲小管对白蛋白的摄取。与对照组一样，在髓袢之外没有可测量的蛋白质摄取。这些结果表明，白蛋白的肾小管重吸收实际上在远曲小管早期就已完成。发现马来酸是近曲小管中蛋白质转运的有效抑制剂，导致白蛋白的分数排泄率为50%。
