Department of Pathology, The University of Rochester School of Medicine and Dentistry, Rochester, New York.
J Exp Med. 1940 Jul 31;72(2):149-65. doi: 10.1084/jem.72.2.149.
Simultaneous hemoglobin and creatinine renal clearance studies have been presented which indicate that hemoglobin is eliminated by the kidney at a rate which is 3 per cent of the creatinine clearance, above a plasma hemoglobin concentration of approximately 250 mg. per 100 cc. In dogs whose average glomerular filtration rate is 66 cc. per minute, about 2 cc. of plasma are cleared of hemoglobin per minute. A definite renal threshold exists for hemoglobin at a plasma concentration of about 100 mg. per 100 cc., below which hemoglobinuria does not occur. The uniformity of the process indicates that hemoglobinuria is not the result of a transient glomerular injury induced by the hemoglobin. It is tentatively suggested that the experimental results obtained may be interpreted in terms of the following concept. The glomerulus permits the filtration of hemoglobin in amounts directly dependent upon plasma concentration. However, only 3 per cent of all the pores of the membrane are electrostatically large enough to permit the passage of an undissociated hemoglobin molecule. Of that hemoglobin which passes down the tubule, a relatively constant though small amount is recovered by the tubules by a process not unlike that of phagocytosis found elsewhere in the body. An average value for this "athrocytic" capacity in a medium-sized dog is 2 mg. of hemoglobin per minute. This pattern of renal hemoglobin excretion is in agreement with the principles of the modern theory of kidney function.
同时进行的血红蛋白和肌酐肾清除率研究表明，当血浆血红蛋白浓度超过约 250mg/100cc 时，血红蛋白以肌酐清除率的 3%的速度被肾脏清除。在平均肾小球滤过率为 66cc/分钟的狗中，每分钟约有 2cc 的血浆被清除血红蛋白。在血浆浓度约为 100mg/100cc 时，血红蛋白存在明确的肾阈值，低于该浓度则不会发生血红蛋白尿。该过程的一致性表明血红蛋白尿不是血红蛋白引起的短暂肾小球损伤的结果。因此，暂时可以根据以下概念来解释实验结果。肾小球允许根据血浆浓度直接过滤血红蛋白。然而，只有 3%的膜孔具有足够的静电强度，可以允许未离解的血红蛋白分子通过。在流经肾小管的血红蛋白中，相对恒定但数量较少的血红蛋白通过类似于身体其他部位发现的吞噬作用的过程被肾小管回收。在一只中等大小的狗中，这种“红细胞性”的平均容量为每分钟 2 毫克血红蛋白。这种肾脏血红蛋白排泄模式符合现代肾脏功能理论的原则。
