[L-arginine prolonged the efficacy of inhaled nitric oxide on the inhibition of pulmonary hypertension].
OBJECTIVE
The aim of this study is to investigate the effects of L-arginine, the substrate of nitric oxide (NO) on the duration of nitric oxide selective decrease of pulmonary hypertension. To assess whether combined use of inhaled nitric oxide and venous administered L-arginine can improve the efficacy of inhaled NO on the inhibition of hypoxia induced pulmonary hypertension.


METHODS
Eight pigs with hypoxic pulmonary hypertension received either inhaled NO(12-15 ppm) for 10 minutes or inhaled NO plus venous administrered L-arginine(10 g), then hemodynamic parameters were recorded.


RESULTS
NO inhalation significantly inhibited hypoxic induced pulmonary hypertension with pulmonary arterial pressure decreasing from 4.2 +/- 0.4 kPa to 2.5 +/- 0.5 kPa(P < 0.01) and pulmonary vascular resistance from 56 +/- 25 kPa.s.L-1 to 31 +/- 13 kPa.s.L-1(P < 0.01), but this just lasted for 3-5 minutes after stopping inhalation; combined use of L-arginine infusion did not further decrease pulmonary arterial pressure, but significantly prolonged the inhibitory effect of inhaled NO on pulmonary hypertension (20 times) as compared with inhaled NO only.


CONCLUSIONS
With the existence of exogenous NO, supplement of NO substrate L-arginine produced a synesgetic inhibition effect on hypoxic induced pulmonary hypertension.
Xu
Y
Y
Guangzhou Institute of Respiratory Disease, Guangzhou, 510120.
Chen
S
S
Zhong
N
N
D000280:Administration, Inhalation; D000818:Animals; D001120:Arginine / Q000494:pharmacology*; D001794:Blood Pressure / Q000187:drug effects; D004357:Drug Synergism; D005260:Female; D006976:Hypertension, Pulmonary / Q000209:etiology / Q000503:physiopathology*; D000860:Hypoxia / Q000150:complications; D008297:Male; D009569:Nitric Oxide / Q000494:pharmacology*; D011651:Pulmonary Artery / Q000503:physiopathology; D013552:Swine; D014655:Vascular Resistance / Q000187:drug effects; D014665:Vasodilator Agents / Q000494:pharmacology
D014665:Vasodilator Agents; D009569:Nitric Oxide; D001120:Arginine