Short-term treatment with L-arginine prevents the smoking-induced impairment of endothelial function and vascular elastic properties in young individuals.
BACKGROUND
L-arginine, the substrate for endothelial nitric oxide synthase, is essential for normal endothelial function. Aim of the present study was to investigate in healthy smokers the effect of a short-term daily L-arginine administration on vascular function.


METHODS
We studied the effect of a 3-day oral administration of L-arginine in 10 healthy smokers (24.3+/-0.73 years old) on 3 occasions (day , day 1 and day 3). The study was carried out on two separate arms, one with L-arginine (7 gr/d) and one with placebo according to a randomized, placebo-controlled, double-blind, cross-over design. Measurements were carried out before, immediately after (Sm0) and 20 min after (Sm20) cigarette smoking. Endothelial function was evaluated by flow-mediated dilatation (FMD) of the brachial artery. Carotid-femoral pulse wave velocity (PWV) was measured as an index of aortic stiffness and augmentation index (AIx) as a measure of arterial wave reflections.


RESULTS
Compared to placebo, L-arginine led to an increase of FMD (p<0.05 at day 2), indicating a favorable effect on endothelial function, which however lost significance at day 3. l-arginine induced a progressive decrease of PWV and AIx at both day 2 and day 3 (p<0.01 vs baseline for all). L-arginine blunted the acute smoking-induced increase of AIx at both day 1 (p<0.05) and day 3 (p<0.01), and there was a trend to protect the smoking-induced change of PWV at day 3 (p<0.1).


CONCLUSIONS
Short-term daily administration of L-arginine improves arterial performance in healthy smokers and abrogates the smoking-induced increase in arterial stiffness and wave reflections in these individuals.
Siasos
Gerasimos
G
Athens University Medical School, 1st Cardiology Department, Greece.
Tousoulis
Dimitris
D
Vlachopoulos
Charalambos
C
Antoniades
Charalambos
C
Stefanadi
Elli
E
Ioakeimidis
Nikos
N
Andreou
Ioannis
I
Zisimos
Kostas
K
Papavassiliou
Athanasios G
AG
Stefanadis
Christodoulos
C
D000284:Administration, Oral; D000328:Adult; D000367:Age Factors; D000704:Analysis of Variance; D001120:Arginine / Q000008:administration & dosage*; D002339:Carotid Arteries; D018592:Cross-Over Studies; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D004334:Drug Administration Schedule; D004548:Elasticity / Q000187:drug effects; D004730:Endothelium, Vascular / Q000187:drug effects* / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D011336:Probability; D011673:Pulsatile Flow / Q000187:drug effects*; D012016:Reference Values; D012907:Smoking / Q000009:adverse effects* / Q000188:drug therapy; D013997:Time Factors; D014655:Vascular Resistance / Q000187:drug effects; D014664:Vasodilation / Q000187:drug effects
D001120:Arginine