Sands J M, Kokko J P
Department of Medicine, Emory University School of Medicine, Atlanta, Georgia, USA.
Kidney Int Suppl. 1996 Dec;57:S93-9.
The production of a concentrated urine is achieved by countercurrent multiplication in the renal medulla. While the single effect in the outer medulla is known to be active NaCl reabsorption in the thick ascending limb, the single effect in the inner medulla is not definitively established. However, the passive model of Kokko and Rector [1] and Stephenson [2] remains the most widely accepted mechanism for the single effect in the inner medulla. Continued experimental studies of transport in perfused inner medullary nephron segments and mathematical simulations that incorporate these new experimental values and anatomic complexity will be needed to fully elucidate the process of urinary concentration. In addition, the availability of molecular reagents will permit investigation into the molecular mechanisms that regulate transport proteins which play crucial roles in the urinary concentrating mechanism.
肾髓质中的逆流倍增实现了浓缩尿的生成。虽然已知外髓质中的单效应是厚壁升支中主动重吸收氯化钠，但内髓质中的单效应尚未明确确定。然而，科科和雷克托[1]以及斯蒂芬森[2]的被动模型仍然是内髓质单效应最被广泛接受的机制。需要继续对灌注的内髓质肾单位节段中的转运进行实验研究，并进行纳入这些新实验值和解剖复杂性的数学模拟，以充分阐明尿液浓缩过程。此外，分子试剂的可用性将允许研究调节在尿液浓缩机制中起关键作用的转运蛋白的分子机制。
