title: [Clinical study on the antioxidant effect of methylene blue in vivo].
abstract: OBJECTIVE
  To investigate the relationship of oxygen free radical (OFR) with per-oxidative injury of erythrocyte induced by intravenous procaine in vivo and the effect of methylene blue (MB) in removal of nitric oxide (NO) and peroxynitrite (ONOO(-)).
  
  
  METHODS
  Forty patients undergoing elective surgery were divided randomly into intravenous procaine anesthesia (IPA) group and fentanyl group. Blood sample was taken before anesthesia (T0), 120 minutes (T1) and 180 minutes (T2) after IPA and 30 minutes after treatment with MB (1-2 mg/kg, T3) to determine the changes in the levels of NO, OFR, lipid peroxide (LPO), superoxide dismutase (SOD), catalase (CAT), NADH-Cyt b5-reductase (Cyt b5-R) and methemoglobin (MHb).
  
  
  RESULTS
  Compared with T0, the levels of NO, OFR, LPO, MHb in IPA group were significantly increased at T1,T2. At same time SOD, CAT and Cyt b5-R were significantly decreased. NO, OFR, MHb, SOD, CAT and Cyt b5-R were all reduced to the normal levels at T3. No changes in any determined parameters in fentanyl group during anesthesia.
  
  
  CONCLUSIONS
  It is indicated that the metabolites of procaine consist of a large quantity of NO:ONOO(-), producing per-oxidative injury to erythrocyte. MB is effective in eliminating OFR in vivo, protecting tissue cells. It may act as an antioxidant drug in the treatment of critical illness.
authors.affiliation: Department of Anesthesiology, Haikou People's Hospital, Haikou 570208, Hainan, China.
authors.forename: Min
authors.initials: M
authors.lastname: Liang
authors.forename: Xiao-bin
authors.initials: XB
authors.lastname: Wei
authors.forename: Ai-zhen
authors.initials: AZ
authors.lastname: Wu
authors.forename: Yu-huan
authors.initials: YH
authors.lastname: Huang
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000975:Antioxidants / Q000494:pharmacology*; D002374:Catalase / Q000097:blood / Q000187:drug effects; D005260:Female; D006801:Humans; D008054:Lipid Peroxides / Q000097:blood; D008297:Male; D008706:Methemoglobin / Q000187:drug effects / Q000378:metabolism; D008751:Methylene Blue / Q000494:pharmacology*; D008875:Middle Aged; D009251:NADPH-Ferrihemoprotein Reductase / Q000097:blood / Q000187:drug effects; D009569:Nitric Oxide / Q000097:blood; D030421:Peroxynitrous Acid / Q000097:blood; D017382:Reactive Oxygen Species / Q000097:blood; D013482:Superoxide Dismutase / Q000097:blood / Q000187:drug effects
chemical_list: D000975:Antioxidants; D008054:Lipid Peroxides; D017382:Reactive Oxygen Species; D030421:Peroxynitrous Acid; D009569:Nitric Oxide; D008706:Methemoglobin; D002374:Catalase; D013482:Superoxide Dismutase; D009251:NADPH-Ferrihemoprotein Reductase; D008751:Methylene Blue