CALCIUM-OXALATE NEPHROLITHIASIS, A FREE OR FIXED PARTICLE DISEASE
CALCIUM-OXALATE NEPHROLITHIASIS, A FREE OR FIXED PARTICLE DISEASE
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DOI：
10.1038/ki.1994.341
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发表时间：
1994-09-01
影响因子：
19.6
通讯作者：
KHAN, SR
中科院分区：
文献类型：
--
作者：
KOK, DJ;KHAN, SR
使用Finlayson和Reid [1]的方法计算通过自由颗粒机制发生结石形成的机会。对于这些计算，我们使用了新的数据，肾单位的尺寸，过饱和度和晶体生长速率在尿液中，也纳入了晶体团聚的大小增加的效果。假设不同水平的草酸排泄进行计算，模拟昼夜变化和急性高尿酸饮食负荷后。此外，尿流状况根据每日尿量的变化而变化。结果表明，在尿液通过肾单位的正常传输时间内，颗粒可以获得足够大的尺寸以保留在肾单位中。这主要是由于附聚过程的尺寸增加效应。存在的草酸盐的可沉淀量不限制最大可获得的粒度。然而，草酸盐排泄的急性增加确实会带来风险，因为肾单位中达到过饱和的时间较早，因此晶体颗粒有更多的时间增加尺寸。总之，本计算表明，在通过肾脏的正常通过时间期间，可以形成结晶颗粒，这些结晶颗粒由于其尺寸而大到足以被保留，从而形成结石的病灶。在这些集合管的末端遇到的风险最高，在那里，在肾单位中形成的晶体与Henle长环相遇并聚集。
The chances of stone formation occurring through a free particle mechanism were calculated using the approach of Finlayson and Reid [1]. For these calculations we used new data on nephron dimensions, supersaturation and crystal growth rates in urine, and also incorporated the size increasing effect of crystal agglomeration. The calculations were performed assuming different levels of oxalate excretion, simulating the diurnal variation and acute hyperoxaluria following a dietary load. In addition urinary flow conditions were varied according to changes in daily urinary volume. It is shown that during the normal transit time of urine through the nephron, particles can obtain a size big enough to be retained in the nephron. This is mainly due to the size-increasing effect of the agglomeration process. The precipitable amount of oxalate present is not limiting for the maximum attainable particle size. However, acute increases in oxalate excretion do pose a risk because supersaturation is reached earlier in the nephron and consequently the crystal particles are allowed more time to increase in size. In conclusion, the present calculations demonstrate that during the normal transit time through the kidney, crystalline particles can be formed which are large enough to be retained because of their size and thus form the nidus of a stone. The highest risk is encountered at the end of those collecting ducts where crystals formed in nephrons with a long loop of Henle meet and agglomerate.