The impact of oral L-arginine supplementation on acute smoking-induced endothelial injury and arterial performance.
BACKGROUND
Smoking is associated with endothelial dysfunction and increased inflammatory status. The amino acid L-arginine, improves endothelial function in patients with cardiovascular risk factors. We investigated the effect of L-arginine on vascular function and inflammatory process in healthy smokers at rest and after acute smoking.


METHODS
We studied the effect of L-arginine and/or placebo in 12 healthy young smokers on three occasions (day 0, day 1, and day 3). The study was carried out on two separate arms, one with L-arginine (3 x 7 g/day) and one with placebo, according to a randomized, placebo-controlled, double-blind, cross-over design. Measurements were carried out before, immediately after, and 20 min after cigarette smoking. Endothelial function was evaluated by flow-mediated dilation (FMD). Carotid-femoral pulse wave velocity (PWV) was measured as an index of aortic stiffness and augmentation index (AIx) and as a measure of arterial wave reflections. Serum soluble intercellular adhesion molecule-1 (sICAM-1) was measured.


RESULTS
Compared to placebo, L-arginine improved FMD (P < 0.01 at day 1 and P < 0.05 at day 3). L-Arginine reduced PWV and AIx at both days 1 and 3 (P < 0.05 vs. baseline). L-Arginine blunted the acute smoking-induced increase of AIx at both day 1 (P < 0.05) and day 3 (P < 0.01), and prevented the smoking-induced elevation of PWV at day 3 (P < 0.05). Importantly, L-arginine reduced sICAM-1 at days 1 and 3 (P < 0.05 for both vs. baseline).


CONCLUSIONS
Oral L-arginine improves endothelial function and vascular elastic properties of the arterial tree during the acute phase of smoking, an effect accompanied by reduced sICAM-1 levels in these subjects.
Siasos
Gerasimos
G
Department of Biological Chemistry, Athens University Medical School, Athens, Greece.
Tousoulis
Dimitris
D
Vlachopoulos
Charalambos
C
Antoniades
Charalambos
C
Stefanadi
Elli
E
Ioakeimidis
Nikos
N
Zisimos
Kostas
K
Siasou
Zoi
Z
Papavassiliou
Athanasios G
AG
Stefanadis
Christodoulos
C
D000284:Administration, Oral; D000328:Adult; D001120:Arginine / Q000008:administration & dosage*; D001916:Brachial Artery / Q000000981:diagnostic imaging / Q000187:drug effects / Q000503:physiopathology; D018592:Cross-Over Studies; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D004730:Endothelium, Vascular / Q000187:drug effects / Q000503:physiopathology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D016491:Peripheral Vascular Diseases / Q000209:etiology / Q000503:physiopathology / Q000517:prevention & control*; D012016:Reference Values; D012907:Smoking / Q000009:adverse effects*; D016896:Treatment Outcome; D018616:Ultrasonography, Doppler, Duplex; D014661:Vasoconstriction / Q000187:drug effects / Q000502:physiology*; D055815:Young Adult
D001120:Arginine