Amiry-Moghaddam M, Nagelhus E, Ottersen O P
Department of Anatomy, University of Oslo, Norway.
Kidney Int. 1994 Jan;45(1):10-22. doi: 10.1038/ki.1994.2.
Several lines of evidence suggest that taurine acts as an organic osmolyte in the kidney. We investigated the cellular and subcellular distribution of this amino acid in rat renal tubule cells. Semi- and ultrathin sections of plastic-embedded rat kidney were incubated with an antiserum against conjugated taurine, using peroxidase-antiperoxidase and immunogold procedures, respectively. Extensive control tests confirmed the selectivity of the antiserum. Our immunocytochemical preparations revealed a highly differentiated labeling pattern. Strong labeling (judged visually or by computer-aided calculation of gold particle densities) was found in collecting duct cells throughout cortex and medulla, in proximal straight tubule cells, and in cells of the descending thin limbs of Henle's loop. Intermediate gold particle densities occurred in proximal convoluted tubule cells and intercalated cells of the collecting ducts (the gold particle in the latter being 30% of that in the collecting duct cells). The distal convoluted tubules, and thick and thin ascending limbs were almost immunonegative. It cannot be excluded that the proportion of free taurine that is retained by the fixative varies somewhat among the different cell types. Yet the highly differentiated labeling pattern that was obtained suggests that taurine is heterogeneously distributed among different populations of tubule cells, and that its level varies substantially even among cells that are exposed to the same osmotic stress.
多条证据表明，牛磺酸在肾脏中作为一种有机渗透剂发挥作用。我们研究了这种氨基酸在大鼠肾小管细胞中的细胞和亚细胞分布。分别使用过氧化物酶 - 抗过氧化物酶和免疫金法，将塑料包埋的大鼠肾脏的半薄切片和超薄切片与抗结合型牛磺酸的抗血清孵育。广泛的对照试验证实了抗血清的选择性。我们的免疫细胞化学制剂显示出高度分化的标记模式。在整个皮质和髓质的集合管细胞、近端直小管细胞以及亨氏袢降支细段的细胞中发现强标记（通过视觉判断或通过计算机辅助计算金颗粒密度）。近端曲小管细胞和集合管的闰细胞中出现中等金颗粒密度（后者的金颗粒为集合管细胞中金颗粒的30%）。远曲小管以及粗细升支几乎呈免疫阴性。不能排除固定剂保留的游离牛磺酸比例在不同细胞类型中略有差异。然而，所获得的高度分化的标记模式表明，牛磺酸在不同的肾小管细胞群体中分布不均，并且即使在受到相同渗透应激的细胞中，其水平也有很大差异。
