Titze Jens, Shakibaei Mehdi, Schafflhuber Markus, Schulze-Tanzil Gundula, Porst Markus, Schwind Karl H, Dietsch Peter, Hilgers Karl F
Department of Medicine IV, Friedrich-Alexander-University Erlangen-Nürnberg, Germany.
Am J Physiol Heart Circ Physiol. 2004 Jul;287(1):H203-8. doi: 10.1152/ajpheart.01237.2003. Epub 2004 Feb 19.
Osmotically inactive skin Na(+) storage is characterized by Na(+) accumulation without water accumulation in the skin. Negatively charged glycosaminoglycans (GAGs) may be important in skin Na(+) storage. We investigated changes in skin GAG content and key enzymes of GAG chain polymerization during osmotically inactive skin Na(+) storage. Female Sprague-Dawley rats were fed a 0.1% or 8% NaCl diet for 8 wk. Skin GAG content was measured by Western blot analysis. mRNA content of key dermatan sulfate polymerization enzymes was measured by real-time PCR. The Na(+) concentration in skin was determined by dry ashing. Skin Na(+) concentration during osmotically inactive Na(+) storage was 180-190 mmol/l. Increasing skin Na(+) coincided with increasing GAG content in cartilage and skin. Dietary NaCl loading coincided with increased chondroitin synthase mRNA content in the skin, whereas xylosyl transferase, biglycan, and decorin content were unchanged. We conclude that osmotically inactive skin Na(+) storage is an active process characterized by an increased GAG content in the reservoir tissue. Inhibition or disinhibition of GAG chain polymerization may regulate osmotically inactive Na(+) storage.
渗透性无活性皮肤钠储存的特点是皮肤中钠蓄积但无水蓄积。带负电荷的糖胺聚糖（GAGs）可能在皮肤钠储存中起重要作用。我们研究了渗透性无活性皮肤钠储存期间皮肤GAG含量和GAG链聚合关键酶的变化。将雌性Sprague-Dawley大鼠分别喂食0.1%或8%氯化钠饮食8周。通过蛋白质印迹分析测量皮肤GAG含量。通过实时PCR测量关键硫酸皮肤素聚合酶的mRNA含量。通过干灰化法测定皮肤中的钠浓度。渗透性无活性钠储存期间皮肤钠浓度为180 - 190 mmol/L。皮肤钠增加与软骨和皮肤中GAG含量增加一致。饮食中氯化钠负荷与皮肤中软骨素合酶mRNA含量增加一致，而木糖基转移酶、双糖链蛋白聚糖和核心蛋白聚糖含量未改变。我们得出结论，渗透性无活性皮肤钠储存是一个活跃过程，其特征是储存组织中GAG含量增加。GAG链聚合的抑制或去抑制可能调节渗透性无活性钠储存。
