title: Age-related changes in the protective effect of chronic administration of L-arginine on post-ischemic recovery of endothelial function.
abstract: OBJECTIVE
  The aim of this study was to assess the effect of chronic administration of L-arginine (LA) on vascular functions as well as its age-related changes.
  
  
  METHODS
  Male Sprague-Dawley rats aged 1, 4, 8 and 16 months were divided into control and LA groups, which were administered LA (4 mg/ml) for 6 weeks. Isolated heart perfusion was performed, followed by cardioplegic arrest for 4h at 4 degrees C and reperfusion. Vascular functions were assessed through observations of pre-/post-ischemic coronary flow response to 5-hydroxytryptamine (5-HT) and glyceryl trinitrate (GTN). Ultrastructure was studied after the same ischemia-reperfusion.
  
  
  RESULTS
  A significant improvement of percentage recovery (post-/pre-ischemic value) of response to 5-HT were seen in 4 and 8 months LA group when compared to the control (84.2+/-14.0 vs. 33.9+/-12.5 (P<0.05) and 97.0+/-23.2 vs. 21.5+/-9.7 (P<0.05), respectively). Furthermore, 8 months LA group had better percentage recovery of response to GTN (124.5+/-41.6 vs. 47.7+/-6.3, P<0.05). Ultrastructural study showed no significant differences between the groups in any age.
  
  
  CONCLUSIONS
  Chronic oral administration of LA enhanced the post-ischemic recovery of vascular function in the young adult and adult hearts, but not in the infant and elderly.
authors.affiliation: National Heart and Lung Institute, Heart Science Centre, Harefield Hospital, Harefield, Middlesex UB9 6JH, UK.
authors.forename: Koki
authors.initials: K
authors.lastname: Nakamura
authors.forename: Sharif
authors.initials: S
authors.lastname: Al-Ruzzeh
authors.forename: Adrian H
authors.initials: AH
authors.lastname: Chester
authors.forename: Ann
authors.initials: A
authors.lastname: Dewar
authors.forename: Steve
authors.initials: S
authors.lastname: Rothery
authors.forename: Nicholas J
authors.initials: NJ
authors.lastname: Severs
authors.forename: Magdi H
authors.initials: MH
authors.lastname: Yacoub
authors.forename: Mohamed
authors.initials: M
authors.lastname: Amrani
mesh_terms: D000375:Aging / Q000502:physiology*; D000818:Animals; D001120:Arginine / Q000097:blood / Q000627:therapeutic use*; D004730:Endothelium, Vascular / Q000187:drug effects* / Q000473:pathology / Q000503:physiopathology; D008297:Male; D023421:Models, Animal; D009131:Muscle, Smooth, Vascular / Q000187:drug effects / Q000473:pathology / Q000503:physiopathology; D015428:Myocardial Reperfusion Injury / Q000097:blood / Q000503:physiopathology / Q000517:prevention & control*; D009569:Nitric Oxide / Q000097:blood; D005996:Nitroglycerin / Q000494:pharmacology; D010477:Perfusion; D051381:Rats; D017207:Rats, Sprague-Dawley; D012701:Serotonin / Q000494:pharmacology; D014665:Vasodilator Agents / Q000494:pharmacology
chemical_list: D014665:Vasodilator Agents; D009569:Nitric Oxide; D012701:Serotonin; D001120:Arginine; D005996:Nitroglycerin