title: Eplerenone inhibits aldosterone-induced renal expression of cyclooxygenase.
abstract: BACKGROUND
  The upregulation of cyclooxygenase (COX) expression by aldosterone (ALDO) or high salt diet intake is very interesting and complex in the light of what is known about the role of COX in renal function. Thus, in this study, we hypothesize that apocynin (APC) and/or eplerenone (EPL) inhibit ALDO/salt-induced kidney damage by preventing the production of prostaglandin E₂ (PGE₂).
  
  
  METHODS
  Dahl salt-sensitive rats on either a low-salt or high-salt diet were treated with ALDO (0.2 mg pellet) in the presence of EPL (100 mg/kg/day) or APC (1.5 mM). Indirect blood pressure, prostaglandins and ALDO levels and histological changes were measured.
  
  
  RESULTS
  Cyclooxygenase-2 (COX-2) levels were upregulated in the renal tubules and peritubular vessels after high-salt intake, and APC attenuated renal tubular COX-2 protein expression induced by ALDO. Plasma PGE₂ levels were significantly reduced by ALDO in the rats fed a low-salt diet when compared to rats fed a high-salt diet. PGE₂ was blocked by EPL but increased in the presence of APC.
  
  
  CONCLUSIONS
  The beneficial effects of EPL may be associated with an inhibition of PGE₂. The mechanism underlying the protective effects of EPL is clearly distinct from that of APC and suggests that these agents can have differential roles in cardiovascular disease.
authors.affiliation: Department of Pharmacology/Toxicology, Morehouse School of Medicine, Atlanta, Georgia 30310, USA. mbayorh@msm.edu
authors.forename: Ma
authors.initials: M
authors.lastname: Bayorh
authors.forename: A
authors.initials: A
authors.lastname: Rollins-Hairston
authors.forename: J
authors.initials: J
authors.lastname: Adiyiah
authors.forename: D
authors.initials: D
authors.lastname: Lyn
authors.forename: D
authors.initials: D
authors.lastname: Eatman
mesh_terms: D000098:Acetophenones / Q000494:pharmacology; D000450:Aldosterone / Q000494:pharmacology*; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D015153:Blotting, Western; D051545:Cyclooxygenase 1 / Q000378:metabolism*; D051546:Cyclooxygenase 2 / Q000378:metabolism*; D015232:Dinoprostone / Q000097:blood; D000077545:Eplerenone; D011464:Epoprostenol / Q000097:blood; D006339:Heart Rate / Q000187:drug effects; D007150:Immunohistochemistry; D007668:Kidney / Q000166:cytology / Q000187:drug effects* / Q000201:enzymology*; D008297:Male; D008565:Membrane Proteins / Q000378:metabolism*; D051381:Rats; D020303:Rats, Inbred Dahl; D013148:Spironolactone / Q000031:analogs & derivatives* / Q000494:pharmacology; D013599:Systole / Q000187:drug effects; D014662:Vasoconstrictor Agents / Q000494:pharmacology
chemical_list: D000098:Acetophenones; D008565:Membrane Proteins; D014662:Vasoconstrictor Agents; D013148:Spironolactone; D000450:Aldosterone; D000077545:Eplerenone; C056165:acetovanillone; D011464:Epoprostenol; D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2; C496513:Ptgs1 protein, rat; C489691:Ptgs2 protein, rat; D015232:Dinoprostone