title: Neurotrophic factor expression after focal brain ischemia preceded by different preconditioning strategies.
abstract: BACKGROUND
  Both prolonged brain ischemia and preconditioning (PC) induce expression of neurotrophic factors. However, the influence of PC on their expression after a long-term ischemia remains vague. Previously, we have found various effects of PC on mRNA levels of different cytokines after focal brain ischemia. Thus, we investigated mRNA expression of nerve growth factor, brain-derived neurotrophic factor (BDNF) and ciliary neurotrophic factor after 90-min middle cerebral artery occlusion (MCAo) preceded by ischemic or chemical PC.
  
  
  METHODS
  MCAo was induced in rats using the suture method. PC had been carried out 3 days earlier. There were 4 experimental groups: MCAo alone; ischemic PC and MCAo; chemical PC and MCAo, and sham-operated rats. Expression of mRNAs in the ipsi- and contralateral cortex was studied by semiquantitative RT-PCR at 12 and 24 h after MCAo.
  
  
  RESULTS
  Despite clearly neuroprotective effects of both PC strategies, mRNA levels of neurotrophic factors were similar in tolerant and nontolerant rats. Only BDNF mRNA expression, 12 h after reperfusion, was lower when ischemic PC was applied prior to long-term ischemia.
  
  
  CONCLUSIONS
  These results suggest that PC generally does not change the expression of neurotrophic factor expression after a long-term focal brain ischemia compared to the nontolerant state.
authors.affiliation: Department of Neurology, Jagiellonian University, Krakow, Poland. pera@neuro.cm-uj.krakow.pl
authors.forename: Joanna
authors.initials: J
authors.lastname: Pera
authors.forename: Malgorzata
authors.initials: M
authors.lastname: Zawadzka
authors.forename: Bozena
authors.initials: B
authors.lastname: Kaminska
authors.forename: Andrzej
authors.initials: A
authors.lastname: Szczudlik
mesh_terms: D000818:Animals; D000959:Antihypertensive Agents / Q000494:pharmacology; D002545:Brain Ischemia / Q000503:physiopathology*; D019208:Brain-Derived Neurotrophic Factor / Q000235:genetics; D020934:Ciliary Neurotrophic Factor / Q000235:genetics; D015870:Gene Expression / Q000187:drug effects; D020244:Infarction, Middle Cerebral Artery / Q000503:physiopathology; D019194:Ischemic Preconditioning; D008297:Male; D020932:Nerve Growth Factor / Q000235:genetics*; D009574:Nitro Compounds; D011422:Propionates / Q000494:pharmacology; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D017208:Rats, Wistar
chemical_list: D000959:Antihypertensive Agents; D019208:Brain-Derived Neurotrophic Factor; D020934:Ciliary Neurotrophic Factor; D009574:Nitro Compounds; D011422:Propionates; D012333:RNA, Messenger; D020932:Nerve Growth Factor; C015392:3-nitropropionic acid