title: Forearm reactive hyperaemia is not mediated by nitric oxide in healthy volunteers.
abstract: OBJECTIVE
  To determine the role of nitric oxide (NO) in forearm reactive hyperaemia in healthy human subjects.
  
  
  METHODS
  Ten healthy subjects aged 19-34 years underwent brachial artery cannulation. Forearm circulatory arrest was achieved by means of an upper arm cuff inflated to 200 mmHg for 5 min. The blood flow responses during reactive hyperaemia were measured using venous occlusion plethysmography following a 10 min intra-arterial infusion of 8 micromol min-1 N-monomethyl L-arginine (L-NMMA) and following matching placebo administered in random order. Results were analysed by repeated measures anova and t-tests.
  
  
  RESULTS
  L-NMMA resulted in a significant reduction of basal forearm blood flow indicating inhibition of basal NO release (P=0.005). There was no significant difference between the blood flow responses during reactive hyperaemia following L-NMMA and placebo (P=0.97).
  
  
  CONCLUSIONS
  Nitric oxide production does not make a significant contribution to the vasodilatation associated with reactive hyperaemia in the human forearm.
authors.affiliation: Department of Therapeutics and Pharmacology, The Queen's University of Belfast, Northern Ireland.
authors.forename: A G
authors.initials: AG
authors.lastname: Nugent
authors.forename: C
authors.initials: C
authors.lastname: McGurk
authors.forename: D
authors.initials: D
authors.lastname: McAuley
authors.forename: S
authors.initials: S
authors.lastname: Maguire
authors.forename: B
authors.initials: B
authors.lastname: Silke
authors.forename: G D
authors.initials: GD
authors.lastname: Johnston
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D004791:Enzyme Inhibitors / Q000009:adverse effects; D005260:Female; D005542:Forearm; D006801:Humans; D006940:Hyperemia / Q000139:chemically induced / Q000209:etiology* / Q000503:physiopathology; D008297:Male; D009569:Nitric Oxide / Q000502:physiology*; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors; D012039:Regional Blood Flow / Q000187:drug effects; D019323:omega-N-Methylarginine / Q000009:adverse effects
chemical_list: D004791:Enzyme Inhibitors; D019323:omega-N-Methylarginine; D009569:Nitric Oxide; D019001:Nitric Oxide Synthase