Long-term oral administration of L-arginine enhances endothelium-dependent vasorelaxation and inhibits neointimal thickening after endothelial denudation in rats.
OBJECTIVE
To further prove the hypothesis that local decrease of nitric oxide (NO) synthesis and/or its activity might be critically important in the disturbance of vascular homeostasis after vascular injuries.


METHODS
Intimal thickening model induced by air-drying denudation of rat right common carotid artery was performed to evaluate the effects of long-term oral administration of L-arginine on neointimal thickening and acetylcholine-induced endothelium-dependent vasorelaxation (EDR) by histomorphometric and functional studies.


RESULTS
Reductions in EDR function persisted and simultaneously developed prominent neointimal thickening by 14 days after denudation. Long-term oral supplementation of L-arginine (1 g/kg/day) significantly enhanced EDR from 43.5% +/- 12.35% to 68.8% +/- 9.0% (n = 10, P < 0.001) and reduced neointimal thickening from 62.45 microns +/- 11.26 microns to 21.45 microns +/- 6.34 microns (n = 10, P < 0.001) as compared with each control animals.


CONCLUSIONS
This study shows that oral administration of L-arginine significantly inhibits neointimal thickening and preserves NO-mediated EDR in experimental endothelial denudation, suggesting an important role for L-arginine, NO pathway in the regulation of vascular homeostasis after endothelial injury which might be salutary in prevention restenosis after coronary angioplasty.
Wu
Z
Z
Department of Cardiology, Zhujiang Hospital, First Military Medical University, Guangzhou.
Qian
X
X
Cai
D
D
Liu
Y
Y
Li
Z
Z
He
J
J
D000284:Administration, Oral; D000818:Animals; D001120:Arginine / Q000494:pharmacology*; D017536:Carotid Artery, Common / Q000473:pathology; D004730:Endothelium, Vascular / Q000187:drug effects* / Q000473:pathology; D008297:Male; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors; D010975:Platelet Aggregation Inhibitors / Q000494:pharmacology*; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D017539:Tunica Intima / Q000473:pathology; D014665:Vasodilator Agents / Q000494:pharmacology*
D010975:Platelet Aggregation Inhibitors; D014665:Vasodilator Agents; D001120:Arginine; D019001:Nitric Oxide Synthase