title: Cisplatin decreases renal cyclooxygenase-2 expression and activity in rats.
abstract: OBJECTIVE
  Cisplatin (CP) induced acute renal failure (ARF) has previously been associated with decreased urinary prostaglandin E2 (PGE2) excretion and reduced aquaporin 2 (AQP2) expression in kidney collecting duct. In this study we examined the expression of cyclooxygenase (COX)-1 and -2 as well as AQP2 and the Na-K-2Cl cotransporter in kidneys from rats with CP induced ARF.
  
  
  METHODS
  Rats were treated with either CP or saline and followed for 5 days. Kidneys were dissected into three zones and prepared for immunoblotting, quantitative polymerase chain reaction (QPCR) and immunohistochemistry. Renal content and urinary PGE2 excretion was measured.
  
  
  RESULTS
  Cisplatin treatment was associated with polyuria and a significant decreased creatinine clearance. Inner medullary PGE2 content and urinary PGE2 excretion was decreased in CP-treated rats. QPCR and semiquatitative immunoblotting demonstrated that CP treatment reduced COX-2, AQP2 and Na-K-2Cl cotransporter abundance in the different kidney zones, whereas no change in COX-1 was observed. Results were confirmed by immunohistochemistry.
  
  
  CONCLUSIONS
  Cyclooxygenase-2 expression is decreased in inner medulla and cortex. Consistent with this urinary PGE2 levels were reduced. These data suggest that downregulation of COX-2 is responsible for impaired de novo generation of vasodilatory prostaglandins which may play an important role for the CP induced renal vasoconstriction and development of nephropathy.
authors.affiliation: The Water and Salt Research Center, University of Aarhus, Denmark.  
authors.forename: B
authors.initials: B
authors.lastname: Tusgaard
authors.forename: R
authors.initials: R
authors.lastname: Nørregaard
authors.forename: A M
authors.initials: AM
authors.lastname: Jensen
authors.forename: G
authors.initials: G
authors.lastname: Wang
authors.forename: S O
authors.initials: SO
authors.lastname: Topcu
authors.forename: Y
authors.initials: Y
authors.lastname: Wang
authors.forename: S
authors.initials: S
authors.lastname: Nielsen
authors.forename: J
authors.initials: J
authors.lastname: Frøkiaer
mesh_terms: D058186:Acute Kidney Injury / Q000139:chemically induced; D000818:Animals; D000970:Antineoplastic Agents / Q000009:adverse effects / Q000494:pharmacology*; D051399:Aquaporin 2 / Q000378:metabolism; D002945:Cisplatin / Q000009:adverse effects / Q000494:pharmacology*; D051545:Cyclooxygenase 1 / Q000235:genetics / Q000378:metabolism; D051546:Cyclooxygenase 2 / Q000235:genetics / Q000378:metabolism*; D015232:Dinoprostone / Q000652:urine; D019746:Intramolecular Oxidoreductases / Q000235:genetics / Q000378:metabolism; D007668:Kidney / Q000187:drug effects* / Q000378:metabolism*; D007677:Kidney Function Tests; D008297:Male; D016595:Misoprostol / Q000494:pharmacology; D010120:Oxytocics / Q000494:pharmacology; D000071876:Prostaglandin-E Synthases; D051381:Rats; D017208:Rats, Wistar; D028021:Sodium-Potassium-Chloride Symporters / Q000378:metabolism
chemical_list: D000970:Antineoplastic Agents; D051399:Aquaporin 2; D010120:Oxytocics; D028021:Sodium-Potassium-Chloride Symporters; D016595:Misoprostol; D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2; D019746:Intramolecular Oxidoreductases; D000071876:Prostaglandin-E Synthases; D015232:Dinoprostone; D002945:Cisplatin