Basgen J M, Steffes M W, Stillman A E, Mauer S M
University of Minnesota Medical School, Minneapolis.
Kidney Int. 1994 Jun;45(6):1668-72. doi: 10.1038/ki.1994.218.
In the past researchers have used an estimate of one million as the number of glomeruli in each human kidney. However, recent work on excised kidneys has demonstrated a large variation in glomerular number from one person to another (330,000 to 1,400,000) per kidney. Theoretically an in situ estimate of glomerular number could be obtained if renal cortical volume, volume density of glomeruli per cortex [Vv(glom/cortex)] and mean glomerular volume are known. We used a dog model to demonstrate that an accurate estimate of cortical volume could be obtained in situ using magnetic resonance imaging (MRI). Vv(glom/cortex) and mean glomerular volume were obtained from needle biopsies. An independent and more direct method (the fractionator) was used to validate the estimate of glomerular number obtained using MRI and renal biopsy. On average there was very good agreement between the fractionator method (379,000 +/- 40,000) and the MRI/renal biopsy method (376,000 +/- 108,000) for the 10 dog kidneys measured; however we found up to a 36% difference between the two methods in an individual kidney. Nonetheless, the estimate from the MRI/renal biopsy method has more precision than the assumption that there are one million glomeruli per human kidney.
过去，研究人员估计每个人类肾脏中的肾小球数量为100万个。然而，最近对切除肾脏的研究表明，每个人的每个肾脏的肾小球数量存在很大差异（33万至140万）。从理论上讲，如果已知肾皮质体积、每皮质肾小球的体积密度[Vv(肾小球/皮质)]和平均肾小球体积，就可以获得肾小球数量的原位估计值。我们使用狗模型来证明，利用磁共振成像（MRI）可以在原位获得准确的皮质体积估计值。Vv(肾小球/皮质)和平均肾小球体积通过针吸活检获得。使用一种独立且更直接的方法（分样法）来验证通过MRI和肾活检获得的肾小球数量估计值。在所测量的10只狗的肾脏中，分样法（379,000±40,000）与MRI/肾活检法（376,000±108,000）平均有非常好的一致性；然而，我们发现个别肾脏中这两种方法之间的差异高达36%。尽管如此，MRI/肾活检法的估计比假设每个人类肾脏有100万个肾小球更精确。
