title: Renal hyaluronan accumulation and hyaluronan synthase expression after ischaemia-reperfusion injury in the rat.
abstract: BACKGROUND
  Hyaluronan (HA) is a connective tissue component with unique water binding and pro-inflammatory properties. It has been suggested that HA is involved in normal renal water handling but also in several pathological conditions such as organ rejection and ischaemia-reperfusion (IR) injury.
  
  
  METHODS
  In anaesthetized normal rats we investigated if renal cortical HA accumulation and the intrarenal distribution and expression of HA synthases (Has 1, 2 and 3) correlate with renal dysfunction after renal IR injury. After 20, 30 or 45 min of unilateral renal ischaemia and 72 h of reperfusion, renal function and cortical HA content were measured. Has 1, 2 and 3 mRNA were determined in control and IR kidneys subjected to 45 min ischaemia and 72 h reperfusion.
  
  
  RESULTS
  IR kidneys had reduced urine concentrating ability, potassium excretion, glomerular filtration rate (GFR) and renal blood flow. On average, IR kidneys had more than 10 times higher amounts of cortical HA than the contralateral control kidney and their water content was elevated while medullary HA was largely unaffected. Has 2 expression in the cortex was heavily up-regulated in IR kidneys while Has 3 remained at control levels. Has 1 could never be detected. There was a direct correlation between the amount of cortical HA and the time period of ischaemia and also between the cortical amount of HA and depression of functional parameters.
  
  
  CONCLUSIONS
  IR injury depresses parameters of renal function, which coincides with an elevated cortical HA content and Has 2 expression. The enhanced Has 2 expression indicates that the cortical HA accumulation is primarily dependent on increased HA synthesis and not impaired degradation/elimination. The water binding and pro-inflammatory properties of HA may contribute to renal dysfunction after IR.
authors.affiliation: Division of Integrative Physiology, Department of Medical Cell Biology, Uppsala University, BMC, PO Box 571, SE-751 23 Uppsala, Sweden.
authors.forename: Viktoria
authors.initials: V
authors.lastname: Göransson
authors.forename: Cecilia
authors.initials: C
authors.lastname: Johnsson
authors.forename: Annica
authors.initials: A
authors.lastname: Jacobson
authors.forename: Paraskevi
authors.initials: P
authors.lastname: Heldin
authors.forename: Roger
authors.initials: R
authors.lastname: Hällgren
authors.forename: Peter
authors.initials: P
authors.lastname: Hansell
mesh_terms: D000818:Animals; D014453:Glucuronosyltransferase; D000076002:Hyaluronan Synthases; D006820:Hyaluronic Acid / Q000378:metabolism*; D007668:Kidney / Q000378:metabolism* / Q000473:pathology; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D015427:Reperfusion Injury / Q000378:metabolism*; D014166:Transferases / Q000096:biosynthesis*
chemical_list: D006820:Hyaluronic Acid; D014166:Transferases; D014453:Glucuronosyltransferase; D000076002:Hyaluronan Synthases