Short-term oral administration of L-arginine improves hemodynamics and exercise capacity in patients with precapillary pulmonary hypertension.
We sought to assess the effects of oral supplementation of L-arginine, the precursor of nitric oxide (NO), on hemodynamics and exercise capacity in patients with pulmonary hypertension. Acute hemodynamic responses to oral L-arginine (0.5 g/10 kg body weight) or placebo were examined in 19 patients with primary or precapillary secondary pulmonary hypertension. Cardiopulmonary exercise tests were performed to measure peak oxygen consumption (peak V O(2)) and the ventilatory response to carbon dioxide production (V E-V CO(2) slope) before and 1 wk after treatment with L-arginine (1.5 g/10 kg body weight/d) or placebo. Oral supplementation of L-arginine significantly increased plasma L-citrulline, which indicated enhancement of NO production. Supplemental L-arginine produced a 9% decrease in mean pulmonary arterial pressure (53 +/- 4 to 48 +/- 4 mm Hg, p < 0.05) and a 16% decrease in pulmonary vascular resistance (14.8 +/- 1.5 to 12.4 +/- 1.4 Wood units, p < 0.05). L-arginine modestly decreased mean systemic arterial pressure (92 +/- 4 to 87 +/- 3 mm Hg, p < 0.05). A 1-wk supplementation of L-arginine resulted in a slight increase in peak V O(2) (831 +/- 88 to 896 +/- 92 ml/min, p < 0.05) and a significant decrease in the V E- V CO(2) slope (43 +/- 4 to 37 +/- 3, p < 0.05) without significant systemic hypotension. Hemodynamics and exercise capacity remained unchanged during placebo administration. These results suggest that oral supplementation of L-arginine may have beneficial effects on hemodynamics and exercise capacity in patients with precapillary pulmonary hypertension.
Department of Internal Medicine and Department of Pharmacy, National Cardiovascular Center, and Osaka Seamen's Insurance Hospital, Osaka, Japan.
N
N
Nagaya
M
M
Uematsu
H
H
Oya
N
N
Sato
F
F
Sakamaki
S
S
Kyotani
K
K
Ueno
N
N
Nakanishi
M
M
Yamagishi
K
K
Miyatake
D000284:Administration, Oral; D000704:Analysis of Variance; D001120:Arginine / Q000008:administration & dosage*; D004311:Double-Blind Method; D004334:Drug Administration Schedule; D017079:Exercise Tolerance / Q000187:drug effects*; D005260:Female; D005500:Follow-Up Studies; D006439:Hemodynamics / Q000187:drug effects*; D006801:Humans; D006976:Hypertension, Pulmonary / Q000188:drug therapy* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D011336:Probability; D012016:Reference Values; D016896:Treatment Outcome
D001120:Arginine