Hoyer J R, Sisson S P, Vernier R L
Lab Invest. 1979 Aug;41(2):168-73.
Tamm-Horsfall urinary glycoprotein (TH) is the primary constituent of urinary casts. The intracellular distribution of TH in normal rat kidney was determined by immunoelectron microscopy using horseradish peroxidase-labeled antibodies and compared with morphologic localization of TH by immunofluorescence and light immunoperoxidase microscopy. Electron microscopy revealed an intracellular localization of TH restricted to the thick ascending limb of the loop of Henle (ALH). In this nephron segment, TH was distributed on and between adjacent intercellular membranes and infolding intracellular membranes at the base of these cells, within Golgi vacuoles, apical vesicles, and on the luminal membranes. Macula densa cells were negative, although typical ALH cells across the lumen of the same tubular segment were positive. Other renal segments were negative for intracellular TH. The unique distribution of TH is consistent with the known function of the ALH as the diluting segment of the nephron. We speculate that the aggregation and gel formation of TH on and between ALH surface membranes may restrict water movement across the ALH. This influence on permeability would be an important role for TH in the generation of concentration gradients for the countercurrent multiplier system of the kidney.
Tamm-Horsfall尿糖蛋白（TH）是尿沉渣的主要成分。利用辣根过氧化物酶标记抗体，通过免疫电子显微镜确定了TH在正常大鼠肾脏中的细胞内分布，并与免疫荧光和光免疫过氧化物酶显微镜下TH的形态学定位进行了比较。电子显微镜显示TH的细胞内定位局限于髓袢升支粗段（ALH）。在这个肾单位节段中，TH分布于相邻细胞间膜上和细胞间、这些细胞底部的内褶细胞膜上、高尔基液泡内、顶端小泡上以及管腔膜上。致密斑细胞呈阴性，尽管同一肾小管节段管腔内典型的ALH细胞呈阳性。其他肾节段细胞内TH呈阴性。TH的独特分布与已知的ALH作为肾单位稀释节段的功能一致。我们推测，TH在ALH表面膜上和之间的聚集及凝胶形成可能会限制水通过ALH的移动。这种对通透性的影响可能是TH在肾脏逆流倍增系统浓度梯度形成中发挥的重要作用。
