Renal excretion and cyst accumulation of beta 2microglobulin in polycystic kidney disease.
Renal excretion and cyst accumulation of beta 2microglobulin in polycystic kidney disease.
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多囊肾病中 β2 微球蛋白的肾脏排泄和囊肿积聚。
DOI：
10.1038/ki.1987.13
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发表时间：
1987
影响因子：
19.6
通讯作者：
Grantham,JJ
中科院分区：
文献类型：
--
作者：
Birenboim,N;Donoso,VS;Huseman,RA;Grantham,JJ
多囊肾病中β2微球蛋白的肾脏排泄和囊肿积聚。为了确定近端小管功能改变的程度，测定了常染色体显性多囊肾病和不同程度肾功能不全患者血清、尿液和囊肿液中β2微球蛋白（β2m）的含量。6名正常受试者分数排泄（FEβ2m）为0.11±0.03%，9名血清肌酐水平低于1.6 mg/dl的患者分数排泄（FEβ2m）为0.13±0.05%。在5例血清肌酐水平高于3.0 mg/dl的患者中，fe β2m升高（范围为3.5% ~ 196%），血清水平高于正常水平（30,600±6,910µg/l vs. 1,268±111）。7例患者中33例近端囊肿（囊肿/血清Na > 0.8） β2m水平与血清（囊肿/血清β2m 0.98±0.20）相当，21例远端囊肿（囊肿/血清Na < 0.4） β2m低于血清（囊肿/血清β2m 0.17±0.07）。两例多囊肾切除术患者移植后数周的液体分析表明，近端囊肿上皮可渗透β2m，但对肌酐或尿素的渗透性较差。这些研究表明，尽管终末期肾功能衰竭，近端囊肿不能形成或维持β2m的梯度，而远端囊肿仍能维持低水平的β2m蛋白。非偶氮常染色体显性多囊肾病患者的fe β2m值正常，而终末期肾脏的远端囊肿β2m水平较低，表明囊性近端肾单位对终尿没有明显贡献。这些发现与相对少量的囊性小管最终损害非囊性肾单位功能的观点一致。
Renal excretion and cyst accumulation of β2microglobulin in polycystic kidney disease. To determine the extent to which proximal tubule function is altered β2microglobulin (β2m), creatinine and Na were measured in serum, urine and cyst fluid of patients with autosomal dominant polycystic kidney disease and various degrees of renal insufficiency. Fractional excretion (FEβ2m) was 0.11 ± 0.03% in six normal subjects and 0.13 ± 0.05% in nine patients with serum creatinine levels less than 1.6 mg/dl. In five patients with serum creatinine levels above 3.0 mg/dl, FEβ2mwas elevated (range 3.5 to 196%) and serum levels were higher than normal (30,600 ± 6,910 µg/liter vs. 1,268 ± 111). In seven patients β2m levels in 33 proximal cysts (cyst/serum Na > 0.8) equalled those in serum (cyst/serum β2m 0.98 ± 0.20), whereas in 21 distal cysts (cyst/serum Na < 0.4) β2m was less than in serum (cyst/serum β2m 0.17 ± 0.07). Analysis of fluid in two patients with polycystic kidney nephrectomy several weeks post-transplant indicated that proximal cyst epithelium is permeable to β2m, but less so than to creatinine or urea. These studies show that proximal cysts cannot develop or maintain gradients for β2m, whereas distal cysts maintain low levels of the protein despite end–stage renal failure. The normal FEβ2mvalues in nonazotemic autosomal dominant polycystic kidney disease patients and the low distal cyst levels of β2m in end-stage kidneys indicate that the cystic proximal nephrons do not contribute appreciably to the final urine. These findings are consistent with the view that a relatively small number of cystic tubules ultimately compromise the function of non-cystic nephrons.