[Role of nitric oxide in flow-dependent vasodilation of human peripheral arteries in vivo].
Experiments performed in isolated arteries or in animals suggested that flow-dependent dilatation of conduit arteries is mediated through the release of endothelium-derived nitric oxide (NO). The present study was designed to assess whether NO also contributes to flow-dependent dilatation of conduit arteries in humans. Radial artery internal diameter was measured in 8 healthy volunteers (age 22 +/- 1 years), using a transcutaneous A-mode echo-tracking system, coupled to a Doppler device for the measurement of radial blood flow. A catheter was inserted in the brachial artery for measurement of arterial pressure and infusion of the L-arginine analogue NG-monomethyl L-arginine (L-NMMA (8 mumol/min for 7 min, infusion rate 0.8 ml/min). Flow-dependent dilatation was evaluated before and after L-NMMA as the response of the radial artery to an acute increase in flow (reactive hyperemia after a 3 min distal cuff occlusion). Release of the occlusion induced a significant increase in radial blood flow (from 27 +/- 4 to 82 +/- 13 ml/min; p < 0.01) followed by a delayed increase in radial diameter (flow-mediated dilatation; from 2.77 +/- 0.13 to 2.85 +/- 0.13 min; p < 0.01), without any change in heart rate or arterial pressure. L-NMMA induced a significant decrease in basal forearm blood flow (from 27 +/- 4 to 14 +/- 2 ml/min; p < 0.05), without affecting basal radial artery diameter, heart rate or arterial pressure.(ABSTRACT TRUNCATED AT 250 WORDS)
Joannides
R
R
Service de pharmacologie, VACOMED, IFRMP, hôpital de Bois Guillaume, CHU, Rouen.
Haefeli
W E
WE
Linder
L
L
Richard
V
V
Thuillez
C
C
Lüscher
T F
TF
D000328:Adult; D001120:Arginine / Q000031:analogs & derivatives / Q000494:pharmacology; D001158:Arteries / Q000187:drug effects; D001783:Blood Flow Velocity; D002985:Clinical Protocols; D005260:Female; D006801:Humans; D008297:Male; D009569:Nitric Oxide / Q000494:pharmacology*; D017534:Radial Artery / Q000187:drug effects*; D014664:Vasodilation / Q000187:drug effects*
D009569:Nitric Oxide; D001120:Arginine
Rôle du monoxyde d'azote dans la vasodilatation débit-dépendante d'une artère périphérique humaine in vivo.