title: Down regulation of cyclooxygenase-2 is involved in delayed neuroprotection by ischemic preconditioning in rats.
abstract: OBJECTIVE
  To examine whether the prostaglandins (PGs) pathway is involved in triggering delayed neuroprotection by ischemic preconditioning (IPC) and evaluate the effects of IPC on cyclooxygenase-2 (COX-2) expression following focal cerebral ischemia and reperfusion in rats.
  
  
  METHODS
  IPC was induced by 10 min of saline infusion into the left internal carotid artery with the right common carotid artery clamped at the same time. Middle cerebral artery occlusion (MCAO) and reperfusion model was produced using intraluminal filament method.
  
  
  RESULTS
  IPC 48 h prior to MCAO significantly reduced infarct area as compared with MCAO alone. A nonselective inhibitor of COX indomethacin (3 mg/kg, ip) applied 1 h prior to or 1 h after IPC failed to affect its protective effects. IPC had no direct effect on the cortex COX-2 mRNA and protein expression 72 h later, but decreased the expression of COX-2 mRNA and protein following ischemia and reperfusion insult.
  
  
  CONCLUSIONS
  PGs pathways was not involved in triggering delayed neuroprotection by IPC, and IPC induced down-regulation of COX-2 following focal cerebral ischemia and reperfusion in rats in vivo.
authors.affiliation: Department of Pharmacology II, Shanghai Institute of Materia Medica, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 201203, China.
authors.forename: Liang
authors.initials: L
authors.lastname: Xiao
authors.forename: Fei-li
authors.initials: FL
authors.lastname: Zhao
authors.forename: Xing-zu
authors.initials: XZ
authors.lastname: Zhu
mesh_terms: D000818:Animals; D001921:Brain / Q000378:metabolism / Q000473:pathology; D051546:Cyclooxygenase 2; D052246:Cyclooxygenase 2 Inhibitors; D016861:Cyclooxygenase Inhibitors / Q000494:pharmacology; D015536:Down-Regulation; D007213:Indomethacin / Q000494:pharmacology; D020244:Infarction, Middle Cerebral Artery / Q000150:complications*; D019194:Ischemic Preconditioning; D008297:Male; D011451:Prostaglandin-Endoperoxide Synthases / Q000096:biosynthesis* / Q000235:genetics; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D015427:Reperfusion Injury / Q000201:enzymology* / Q000209:etiology / Q000473:pathology
chemical_list: D052246:Cyclooxygenase 2 Inhibitors; D016861:Cyclooxygenase Inhibitors; D012333:RNA, Messenger; D051546:Cyclooxygenase 2; D011451:Prostaglandin-Endoperoxide Synthases; D007213:Indomethacin