Glycosaminoglycan polymerization may enable osmotically inactive Na+ storage in the skin

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Enzymes / metabolism
  • Extracellular Matrix Proteins / metabolism
  • Female
  • Glycosaminoglycans / metabolism*
  • In Vitro Techniques
  • Osmosis
  • Polymers / metabolism*
  • Rats
  • Rats, Sprague-Dawley
  • Skin / metabolism*
  • Sodium / metabolism*


  • Enzymes
  • Extracellular Matrix Proteins
  • Glycosaminoglycans
  • Polymers
  • Sodium