L-arginine and L-NAME have no effects on the reendothelialization process after arterial balloon injury.
OBJECTIVE
Growth regulatory properties of nitric oxide (NO) in cultured endothelial cells is controversial. The aim of our study was to investigate the effect of L-arginine, the endogenous NO precursor, and L-NAME, an inhibitor of NO synthase on the reendothelialization process after angioplasty.


METHODS
Fifty-five New Zealand White rabbits underwent denudation of the left iliac artery. After injury the rabbits were randomized in three groups: L-arginine 2.25% (L-arginine, n = 19); NG-nitro-L-arginine methyl ester 15 mg/kg/day (L-NAME, n = 19); and placebo (controls, n = 17). Treatment was solubilized in drinking water. Reendothelialization was evaluated at 4 weeks by macroscopic evaluation of Evans blue staining and endothelial-specific immunostaining (CD-31) on cross sections. Intimal hyperplasia was evaluated by morphometric analysis.


RESULTS
Despite a significant increase in plasma arginine (P = 0.001) and a reduction in intimal hyperplasia (P = 0.003) with L-arginine, neither agent had a significant effect on reendothelialization at 4 weeks (controls = 36 +/- 4%, L-arginine = 43 +/- 3%, L-NAME = 33 +/- 4%; NS).


CONCLUSIONS
These results suggest that, in spite of previously demonstrated effects on neointimal hyperplasia, the NO pathway does not influence the regrowth of macrovascular endothelial cells in vivo.
Six
I
I
Department of Pharmacology, University of Lille, France.
Van Belle
E
E
Bordet
R
R
Corseaux
D
D
Callebert
J
J
Dupuis
B
B
Bauters
C
C
Bertrand
M E
ME
D000704:Analysis of Variance; D000818:Animals; D001120:Arginine / Q000097:blood / Q000494:pharmacology*; D002404:Catheterization / Q000009:adverse effects*; D004730:Endothelium, Vascular / Q000187:drug effects / Q000378:metabolism / Q000473:pathology*; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D006965:Hyperplasia; D008297:Male; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology*; D009569:Nitric Oxide / Q000378:metabolism; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors*; D011817:Rabbits; D011897:Random Allocation; D013997:Time Factors
D004791:Enzyme Inhibitors; D009569:Nitric Oxide; D001120:Arginine; D019001:Nitric Oxide Synthase; D019331:NG-Nitroarginine Methyl Ester