Age-related changes in the protective effect of chronic administration of L-arginine on post-ischemic recovery of endothelial function.
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.
Nakamura
Koki
K
National Heart and Lung Institute, Heart Science Centre, Harefield Hospital, Harefield, Middlesex UB9 6JH, UK.
Al-Ruzzeh
Sharif
S
Chester
Adrian H
AH
Dewar
Ann
A
Rothery
Steve
S
Severs
Nicholas J
NJ
Yacoub
Magdi H
MH
Amrani
Mohamed
M
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
D014665:Vasodilator Agents; D009569:Nitric Oxide; D012701:Serotonin; D001120:Arginine; D005996:Nitroglycerin