title: [Effects of the metabotropic glutamate receptor ligand(s)-4C3HPG on the induction of brain ischemic tolerance in the rat].
abstract: OBJECTIVE
  To explore roles of metabotropic glutamate receptor1/5 (mGluR1/5) in the induction of brain ischemic tolerance (BIT) induced by cerebral ischemic preconditioning (CIP), influences of mGluR1/5 ligand (s)-4-carboxy-3-hydroxy- phenylglycine ((s)-4C3HPG) on the induction of BIT and expression of glial fibrillary acidic protein (GFAP) in the hippocampus were observed.
  
  
  METHODS
  Thionin staining and GFAP immunohistochemistry staining in rat 4 vessel occlusion (4VO) brain ischemic model was used. Thirty-six rats, of which bilateral vertebral arteries were occluded permanently by electrocautery, were divided into the following 4 groups: sham group; ischemic insult group, BIT group and (s)-4C3HPG group. According to dosages of (s)-4C3HPG used, the (s)-4C3HPG group, was further divided into 0.2 mg, 0.04 mg and 0.008 mg subgroups. All the rats were killed 7 d after the operation or the final ischemic treatment.
  
  
  RESULTS
  (1) The ischemic insult for 8 min increased the histological grade (HG), decreased the pyramidal neuronal density (ND) and increased the expression of GFAP significantly (P < 0.05 vs sham) (2) The CIP prevented the above injury changes in the BIT group. (3) The protective effects of the CIP were blocked by (s)-4C3HFG, as manifested by significant increases in HG and decreases in ND in the (s)-4C3HPG group (P < 0.05 vs sham and BIT groups). The changes were proportional with the dosages of (s)-4C3HPG used.
  
  
  CONCLUSIONS
  (s)-4C3HPG could block the induction of BIT induced by CIP, suggested that mGluR1/5 participate in the induction of BIT.
authors.affiliation: Department of Pathophysiology, Institute of Basic Medicine, Hebei Medical University, Shijiazhuang 050017, China.
authors.forename: Rong-Fang
authors.initials: RF
authors.lastname: Feng
authors.forename: Wen-Bin
authors.initials: WB
authors.lastname: Li
authors.forename: Hui-Qing
authors.initials: HQ
authors.lastname: Liu
authors.forename: Qing-Jun
authors.initials: QJ
authors.lastname: Li
authors.forename: Xiao-Ling
authors.initials: XL
authors.lastname: Chen
authors.forename: Ai-Min
authors.initials: AM
authors.lastname: Zhou
authors.forename: Hong-Gang
authors.initials: HG
authors.lastname: Zhao
authors.forename: Jie
authors.initials: J
authors.lastname: Ai
mesh_terms: D000818:Animals; D002545:Brain Ischemia / Q000378:metabolism* / Q000503:physiopathology; D004569:Electroencephalography; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism*; D005998:Glycine / Q000031:analogs & derivatives / Q000494:pharmacology; D019194:Ischemic Preconditioning; D008297:Male; D009457:Neuroglia / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D064529:Receptor, Metabotropic Glutamate 5; D018094:Receptors, Metabotropic Glutamate / Q000037:antagonists & inhibitors / Q000378:metabolism
chemical_list: D005904:Glial Fibrillary Acidic Protein; D064529:Receptor, Metabotropic Glutamate 5; D018094:Receptors, Metabotropic Glutamate; C104077:metabotropic glutamate receptor type 1; C078245:4-carboxy-3-hydroxyphenylglycine; D005998:Glycine