title: Basal NO locally modulates human iliac artery function in vivo.
abstract: We demonstrated previously that endogenous NO influences large-artery distensibility in the ovine hindlimb. However, the role of basal NO in larger human conduit arteries is controversial. The aim of this study was to investigate whether basal production of NO, acting locally, influences iliac artery distensibility in humans. Distensibility was assessed by intra-arterial measurement of the pulse wave velocity. Eighteen subjects, free of significant coronary or iliac artery disease, were studied after diagnostic cardiac catheterization. Simultaneous pressure waveforms were recorded with a high-fidelity dual-pressure sensing catheter, placed in the common iliac artery during intra-arterial infusion of saline (baseline), glyceryl trinitrate (4 nmol/min), or NG-monomethyl-L-arginine (8 and 16 micromol/min). Drugs were infused proximally, via the catheter to perfuse the segment of artery under study, or distally, via the sheath, to control for any reflex changes in flow or sympathetic activation. Velocity was calculated using the foot-to-foot methodology. Six subjects received glyceryl trinitrate and 12 NG-monomethyl-L-arginine. There was no change in velocity after infusion of glyceryl trinitrate or NG-monomethyl-L-arginine via the sheath. However, infusion of glyceryl trinitrate via the catheter significantly reduced velocity by 31.43+/-5.80% (mean+/-SEM; P<0.01; P=0.02 for comparison). Likewise, infusion of the highest dose of NG-monomethyl-L-arginine via the catheter significantly increased velocity by 27.25+/-8.20% (P=0.001; P=0.02 for comparison). Importantly, there was no change in mean arterial blood pressure throughout the studies. These data indicate that under resting conditions, local NO production modulates human iliac artery distensibility and that exogenous NO increases arterial distensibility.
authors.affiliation: Department of Cardiology, Wales Heart Research Institute, College of Medicine, University Hospital of Wales, Cardiff, UK.
authors.forename: Matthias
authors.initials: M
authors.lastname: Schmitt
authors.forename: Albert
authors.initials: A
authors.lastname: Avolio
authors.forename: Ahmad
authors.initials: A
authors.lastname: Qasem
authors.forename: Carmel M
authors.initials: CM
authors.lastname: McEniery
authors.forename: Mark
authors.initials: M
authors.lastname: Butlin
authors.forename: Ian B
authors.initials: IB
authors.lastname: Wilkinson
authors.forename: John R
authors.initials: JR
authors.lastname: Cockcroft
mesh_terms: D001783:Blood Flow Velocity / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004791:Enzyme Inhibitors / Q000008:administration & dosage / Q000494:pharmacology; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D007083:Iliac Artery / Q000187:drug effects / Q000502:physiology*; D007269:Injections, Intra-Arterial; D008297:Male; D008875:Middle Aged; D009569:Nitric Oxide / Q000502:physiology*; D005996:Nitroglycerin / Q000008:administration & dosage / Q000494:pharmacology; D011674:Pulse; D014664:Vasodilation; D014665:Vasodilator Agents / Q000008:administration & dosage / Q000494:pharmacology; D019323:omega-N-Methylarginine / Q000008:administration & dosage / Q000494:pharmacology
chemical_list: D004791:Enzyme Inhibitors; D014665:Vasodilator Agents; D019323:omega-N-Methylarginine; D009569:Nitric Oxide; D005996:Nitroglycerin