Fischereder Michael, Michalke Bernhard, Schmöckel Elisa, Habicht Antje, Kunisch Raphael, Pavelic Ivana, Szabados Bernadette, Schönermarck Ulf, Nelson Peter J, Stangl Manfred
Medizinische Klinik und Poliklinik IV, Renal Division, Klinikum der Ludwig Maximilians Universitaet, Munich, Germany;
Research Unit Analytical Biochemistry, Helmholtz Zentrum München-German Research Center for Environmental Health, Neuherberg, Germany.
Am J Physiol Renal Physiol. 2017 Aug 1;313(2):F319-F325. doi: 10.1152/ajprenal.00703.2016. Epub 2017 Apr 26.
The current paradigm regarding sodium handling in animals and humans postulates that total body sodium is regulated predominately via regulation of extracellular volume. Active sodium storage independent of volume retention is thought to be negligible. However, studies in animals, hypertensive patients, and healthy humans suggest water-free storage of sodium in skin. We hypothesized that tissue sodium concentrations ([Na]) found in humans vary and reflect regulation due to variable glycosaminoglycan content due to variable expression of XYLT-1. Twenty seven patients on dialysis and 21 living kidney transplant donors free of clinically detectable edema were studied. During surgery, abdominal skin, muscle, and arteries were biopsied. [Na] was determined by inductively coupled plasma-optical emission spectrometry, semiquantitative glycosaminoglycan content with Alcian stain, and XYLT-1 expression by real-time PCR. [Na] of arteries were ranging between 0.86 and 9.83 g/kg wet wt and were significantly higher in arteries (4.52 ± 1.82 g/kg) than in muscle (2.03 ± 1.41 g/kg; < 0.001) or skin (3.24 ± 2.26 g/kg wet wt; = 0.038). For individual patients [Na] correlated for skin and arterial tissue ( = 0.440, = 0.012). [Na] also correlated significantly with blinded semiquantitative analysis of glycosaminoglycans staining ( = 0.588, = 0.004). In arteries XYLT-1 expression was also correlated with [Na] ( = 0.392, = 0.003). Our data confirm highly variable [Na] in human skin and muscle and extend this observation to [Na] in human arteries. These data support the hypothesis of water-independent sodium storage via regulated glycosaminoglycan synthesis in human tissues, including arteries.
当前关于动物和人类钠处理的范式假定，总体钠主要通过细胞外液量的调节来调控。独立于容量潴留的活性钠储存被认为可忽略不计。然而，对动物、高血压患者和健康人类的研究表明，皮肤中存在无水钠储存。我们假设，人类组织中的钠浓度（[Na]）存在差异，并反映了由于XYLT-1表达变化导致糖胺聚糖含量不同而产生的调节作用。对27名接受透析的患者和21名无临床可检测水肿的活体肾移植供体进行了研究。手术期间，取腹部皮肤、肌肉和动脉组织进行活检。通过电感耦合等离子体发射光谱法测定[Na]，用阿尔新蓝染色法测定糖胺聚糖的半定量含量，通过实时聚合酶链反应测定XYLT-1的表达。动脉中的[Na]范围在0.86至9.83克/千克湿重之间，动脉中的[Na]（4.52±1.82克/千克）显著高于肌肉（2.03±1.41克/千克；P<0.001）或皮肤（3.24±2.26克/千克湿重；P = 0.038）。对于个体患者，皮肤和动脉组织中的[Na]具有相关性（r = 0.440，P = 0.012）。[Na]也与糖胺聚糖染色的盲法半定量分析显著相关（r = 0.588，P = 0.004）。在动脉中，XYLT-1的表达也与[Na]相关（r = 0.392，P = 0.003）。我们的数据证实了人类皮肤和肌肉中[Na]高度可变，并将这一观察结果扩展至人类动脉中的[Na]。这些数据支持了通过人类组织（包括动脉）中受调控的糖胺聚糖合成进行非水依赖性钠储存的假设。
