title: Cyclosporine A and NAC on the inducible nitric oxide synthase expression and nitric oxide synthesis in rat renal artery cultured cells.
abstract: BACKGROUND
  The immunosuppressor cyclosporine A (CsA) presents the nephrotoxicity as its major side effect that is mostly attributed to a renal vasoconstriction. This may be due to an excessive generation of vasoconstrictors like reactive oxygen species (ROS), or due to a reduction of vasodilators such as the nitric oxide, which in turn, can be caused by increased amounts of ROS. We evaluated the effect of CsA and the antioxidant N-acetylcysteine (NAC) on inducible nitric oxide synthase (iNOS) mRNA expression and nitric oxide synthesis, in rat renal artery vascular smooth muscle cells (rVSMCs) primary culture.
  
  
  METHODS
  In cells treated during 72 hours with CsA (10 microg/mL), its vehicle (control) (10 microL/mL), Escherichia coli lipopolysaccharide (LPS) (100 microg/mL), CsA + LPS, NAC (6.13 mmol/L), or CsA + NAC, we determined the nitric oxide synthesis (Griess and chemiluminescence methods), iNOS expression [reverse transcription-polymerase chain reaction (RT-PCR)] and cell viability (acridine orange method).
  
  
  RESULTS
  In rVSMCs, LPS increased nitric oxide and iNOS expression; CsA decreased basal and LPS-induced nitric oxide and iNOS expression; NAC increased nitric oxide and blunted the nitric oxide reduction caused by CsA, with no effect on iNOS. CsA reduced cell viability.
  
  
  CONCLUSIONS
  In this study, CsA reduced nitric oxide synthesis in rVSMCs, both through iNOS down-regulation and reduction of cell viability, which could be responsible for the vasoconstrictive effect of the CsA. In the effect of CsA on nitric oxide, probably a role is also played by free radical production, as this effect was blunted by NAC.
authors.affiliation: Nephrology Division, Universidade Federal de São Paulo-Escola Paulista de Medicina, Sao Paulo, Brazil.
authors.forename: Camila
authors.initials: C
authors.lastname: Lessio
authors.forename: Fábio
authors.initials: F
authors.lastname: de Assunção Silva
authors.forename: Maria Aparecida
authors.initials: MA
authors.lastname: Glória
authors.forename: Ana Beatriz Galhardi
authors.initials: AB
authors.lastname: Di Tommaso
authors.forename: Margaret
authors.initials: M
authors.lastname: Gori Mouro
authors.forename: Giovana Seno
authors.initials: GS
authors.lastname: Di Marco
authors.forename: Nestor
authors.initials: N
authors.lastname: Schor
authors.forename: Elisa Mieko Suemitsu
authors.initials: EM
authors.lastname: Higa
mesh_terms: D000111:Acetylcysteine / Q000494:pharmacology*; D000818:Animals; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D016572:Cyclosporine / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D007166:Immunosuppressive Agents / Q000494:pharmacology*; D049449:Luminescence; D008297:Male; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000187:drug effects / Q000201:enzymology; D009569:Nitric Oxide / Q000096:biosynthesis / Q000378:metabolism*; D052247:Nitric Oxide Synthase Type II / Q000235:genetics*; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D017208:Rats, Wistar; D012077:Renal Artery / Q000166:cytology / Q000187:drug effects* / Q000201:enzymology
chemical_list: D007166:Immunosuppressive Agents; D012333:RNA, Messenger; D009569:Nitric Oxide; D016572:Cyclosporine; D052247:Nitric Oxide Synthase Type II; C496318:Nos2 protein, rat; D000111:Acetylcysteine