Cytoprotective efficacy and mechanisms of the liposoluble iron chelator 2,2'-dipyridyl in the rat photothrombotic ischemic stroke model.
We examined the efficacy of the liposoluble iron chelator 2,2'-dipyridyl (DP) in reducing histological damage in rats submitted to cerebral ischemia and the mechanisms involved in the potential cytoprotection. For this purpose, DP (20 mg/kg, i.p.) was administered 15 min before and 1 h after induction of cortical photothrombotic vascular occlusion in rat. Histological studies were performed to assess infarct volume (at days 1 and 3 postischemia) and astromicroglial activation (at day 3 postischemia). Damage to endothelial and neuronal cells was evaluated at day 1 postischemia by quantitative measurements of Evans Blue extravasation and N-acetylaspartate levels, respectively. Cerebral blood flow was recorded in the ischemic core by laser-Doppler flowmetry within the 15 min to 2 h period after photothrombosis. At 4-h postischemia, radical oxygen species (ROS) production was evaluated by measuring brain glutathione concentrations. The cortical expression of the proteins heme oxygenase-1 (HO-1) and hypoxia-inducible factor-1alpha (HIF-1alpha) was analyzed by Western blotting at day 1 postischemia. Infarct volume and ischemic damage to endothelial and neuronal cells were significantly reduced by DP treatment. This cytoprotection was associated with a reduction in ROS production, perfusion deficits, and astrocytic activation. DP treatment also resulted in significant changes in HO-1 (+100%) and HIF-1alpha (-50%) protein expression at the level of the ischemic core. These results report the efficacy of the liposoluble iron chelator DP in reducing histological damage induced by permanent focal ischemia.
Laboratoire de Pharmacodynamie et Physiologie Pharmaceutique (L3P), Faculté de Pharmacie, 7, Bd Jeanne d'Arc, BP 87900, 21079 Dijon Cedex, France.
C
C
Demougeot
M
M
Van Hoecke
N
N
Bertrand
A
A
Prigent-Tessier
C
C
Mossiat
A
A
Beley
C
C
Marie
D015082:2,2'-Dipyridyl / Q000737:chemistry / Q000627:therapeutic use*; D000818:Animals; D001253:Astrocytes / Q000187:drug effects / Q000473:pathology; D002545:Brain Ischemia / Q000188:drug therapy* / Q000473:pathology; D002470:Cell Survival / Q000187:drug effects; D002540:Cerebral Cortex / Q000473:pathology; D002544:Cerebral Infarction / Q000473:pathology; D002560:Cerebrovascular Circulation / Q000187:drug effects; D004268:DNA-Binding Proteins / Q000378:metabolism; D005978:Glutathione / Q000378:metabolism; D006419:Heme Oxygenase (Decyclizing) / Q000096:biosynthesis; D051547:Heme Oxygenase-1; D051793:Hypoxia-Inducible Factor 1; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D007502:Iron Chelating Agents / Q000737:chemistry / Q000627:therapeutic use*; D007834:Lasers; D008297:Male; D009457:Neuroglia / Q000187:drug effects / Q000473:pathology; D009474:Neurons / Q000473:pathology; D009687:Nuclear Proteins / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D017382:Reactive Oxygen Species / Q000378:metabolism; D020521:Stroke / Q000188:drug therapy* / Q000473:pathology; D013927:Thrombosis / Q000188:drug therapy / Q000473:pathology; D014157:Transcription Factors / Q000378:metabolism
D004268:DNA-Binding Proteins; C497444:Hif1a protein, rat; D051793:Hypoxia-Inducible Factor 1; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D007502:Iron Chelating Agents; D009687:Nuclear Proteins; D017382:Reactive Oxygen Species; D014157:Transcription Factors; D015082:2,2'-Dipyridyl; D006419:Heme Oxygenase (Decyclizing); D051547:Heme Oxygenase-1; D005978:Glutathione