title: Age as a modifying factor on the effect of antihypertensive therapy in focal stroke in rats.
abstract: OBJECTIVE
  Antihypertensive treatment with hydralazine for 10 weeks but not 6 weeks reduces infarct size in 13-week-old spontaneously hypertensive rats subjected to focal cerebral ischemia. This study was designed to examine whether the duration of treatment needed to reduce infarct size depends on how long hypertension is present before the initiation of antihypertensive therapy.
  
  
  METHODS
  Six-week-old spontaneously hypertensive rats were treated for 6 weeks and 10-month-old spontaneously hypertensive rats for 10 weeks with 20 mg/kg hydralazine added daily to the drinking water. The animals were then subjected to focal cerebral ischemia by tandem permanent common carotid and middle cerebral artery occlusion.
  
  
  RESULTS
  Blood pressure in the treated groups was lower than that in the untreated groups for the entire treatment period in both experiments. Infarct volume in 10-month-old spontaneously hypertensive rats treated for 10 weeks, but not in 6-week-old spontaneously hypertensive rats treated for 6 weeks, was significantly less than in untreated controls (p = 0.02).
  
  
  CONCLUSIONS
  This study emphasizes the importance of duration of antihypertensive treatment in reducing infarct volume in spontaneously hypertensive rats after focal cerebral ischemia and demonstrates that the effect appears to be independent of the duration of hypertension before the initiation of treatment.
authors.affiliation: Department of Neurology, Ohio State University, Columbus 43210.
authors.forename: A
authors.initials: A
authors.lastname: Slivka
mesh_terms: D000367:Age Factors; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects*; D002545:Brain Ischemia / Q000188:drug therapy* / Q000503:physiopathology; D004334:Drug Administration Schedule; D006830:Hydralazine / Q000008:administration & dosage*; D006973:Hypertension / Q000188:drug therapy* / Q000503:physiopathology; D008297:Male; D051381:Rats; D011918:Rats, Inbred SHR; D013997:Time Factors
chemical_list: D006830:Hydralazine