Effect of systemic L-arginine administration on hemodynamics and nitric oxide release in man.
The effects of L-arginine administration on systemic hemodynamics and plasma concentrations of neuro-endocrine hormones and amino acids were investigated in 10 normotensive healthy volunteers. Nitrite/nitrate in urine and cyclic guanosine monophosphate (c-GMP) in plasma were also measured as indicators of release of nitric oxide (NO). L-arginine administration (30 g/300 ml/30 min) caused hypotension (mean arterial pressure; 79.3 +/- 3.9 mmHg fell to 68.8 +/- 2.2 mmHg) with tachycardia (62.3 +/- 2.3 beats/min increased to 67.5 +/- 1.9 beats/min). The plasma concentration of L-arginine before administration was 98.8 +/- 8.2 mumol/l and increased to 7263 +/- 567 mumol/l 20 min after administration. Cardiac output also increased to 127.2 +/- 3.9% by L-arginine administration. Total peripheral resistance was calculated to fall to 65.9 +/- 2.0%. L-arginine administration slightly changed several hormones, but all values were within normal ranges. Nitrite/nitrate in urine increased 142.1 +/- 12.4% compared to the values before L-arginine administration. Plasma concentrations of c-GMP and L-citrulline, the by-product of NO from L-arginine, were also significantly increased by L-arginine administration. All our results provide evidence for the first time that systemically administered L-arginine releases NO in man.
Hishikawa
K
K
Department of Internal Medicine, Keio University School of Medicine, Tokyo, Japan.
Nakaki
T
T
Tsuda
M
M
Esumi
H
H
Ohshima
H
H
Suzuki
H
H
Saruta
T
T
Kato
R
R
D000328:Adult; D000596:Amino Acids / Q000097:blood; D001120:Arginine / Q000494:pharmacology*; D001794:Blood Pressure / Q000187:drug effects; D006152:Cyclic GMP / Q000097:blood; D006339:Heart Rate / Q000187:drug effects; D006439:Hemodynamics / Q000187:drug effects*; D006728:Hormones / Q000097:blood; D006801:Humans; D008297:Male; D009569:Nitric Oxide / Q000378:metabolism*; D009573:Nitrites / Q000652:urine
D000596:Amino Acids; D006728:Hormones; D009573:Nitrites; D009569:Nitric Oxide; D001120:Arginine; D006152:Cyclic GMP