Diamond H S, Meisel A D
Arthritis Rheum. 1975 Nov-Dec;18(6 Suppl):805-9. doi: 10.1002/art.1780180725.
These results are consistent with a model for renal tubular transport of urate in which there is reabsorption of both filtered and secreted urate. Urate secretion greatly exceeds total urate excretion, and most secreted urate is reabsorbed. At least a portion of urate reabsorption occurs at a site distal to or coextensive with the urate secretory site. There appear to be at least two distinct reabsorptive mechanisms for urate. The results of the flow rate and vasopressin studies are consistent with the hypothesis that urate reabsorption occurs in both the distal and the proximal tubule in man. The distal reabsorptive site appears to be quite small. It may be passive since it does not appear to be inhibited by uricosuric drugs. This reabsorptive site may account for less than 15% of total urate reabsorption. Both volume expansion and probenecid may inhibit urate absorption only in the proximal tubule. Thus reabsorption in the proximal tubule coud account for more than 90% of total urate reabsorption. Reabsorption at the postulated collecting duct reabsorptive site appears to be too small in magnitude to account for all reabsorptions of secreted urate. This could be explained if the reabsorptive site in the proximal tubule is coextensive with or distal to the secretory site. Alternatively, there might be two reabsorptive sites in the proximal tubule: a presecretory site accounting for the reabsorption of most filtered urate, and a site either coextensive or distal to the secretory site accounting for a major component of reabsorption of secreted urate. Finally urate reabsorption would also take place in the collecting duct, perhaps at a passive, flow-dependent site.
这些结果与尿酸盐在肾小管转运的模型一致，在该模型中，滤过的和分泌的尿酸盐均有重吸收。尿酸盐分泌量大大超过尿酸盐总排泄量，且大部分分泌的尿酸盐被重吸收。至少一部分尿酸盐重吸收发生在尿酸盐分泌部位的远端或与之重叠的部位。尿酸盐似乎至少有两种不同的重吸收机制。流速和血管加压素研究的结果与以下假设一致，即人类远端小管和近端小管均发生尿酸盐重吸收。远端重吸收部位似乎相当小。它可能是被动的，因为它似乎不受促尿酸排泄药物的抑制。该重吸收部位可能占尿酸盐总重吸收的不到15%。血容量扩充和丙磺舒可能仅抑制近端小管中的尿酸盐重吸收。因此，近端小管中的重吸收可能占尿酸盐总重吸收的90%以上。假定的集合管重吸收部位的重吸收量似乎太小，无法解释分泌的尿酸盐的所有重吸收。如果近端小管中的重吸收部位与分泌部位重叠或在其远端，这一点就可以得到解释。或者，近端小管中可能有两个重吸收部位：一个分泌前部位，负责大部分滤过尿酸盐的重吸收；另一个与分泌部位重叠或在其远端的部位，负责分泌尿酸盐重吸收的主要部分。最后，尿酸盐重吸收也会在集合管中发生，可能发生在一个被动的、与流量相关的部位。
