title: Effects of sympathetic nerve blockade on vasoconstrictive properties of nitric oxide synthase inhibition in sheep.
abstract: OBJECTIVE
  Inhibition of nitric oxide synthase causes intense vasoconstriction. This effect is thought to be dependent on sympathetic nerve activity. Thus, we investigated the vasoconstrictive effects of the nitric oxide synthase inhibitor NG-nitro-L-arginine methyl ester (L-NAME) in sheep, in which a reversible sympathetic block was established by thoracic epidural anesthesia.
  
  
  METHODS
  Sheep (n = 11) were surgically prepared for chronic study. After at least 5 days of recovery, L-NAME was continuously administered and hemodynamics were monitored. This was done in sheep with and without sympathetic blockade in randomized order.
  
  
  RESULTS
  The vasoconstrictive effects of L-NAME were similar in sheep with and without sympathetic blockade.
  
  
  CONCLUSIONS
  The obtained results suggest that the vasoconstrictive properties of nitric oxide synthase inhibitors are independent of sympathetic tone.
authors.affiliation: Department of Anesthesiology and Intensive Care Medicine, University of Münster, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Booke
authors.forename: R
authors.initials: R
authors.lastname: Waurick
authors.forename: H
authors.initials: H
authors.lastname: Van Aken
authors.forename: H G
authors.initials: HG
authors.lastname: Bone
authors.forename: A
authors.initials: A
authors.lastname: Meissner
authors.forename: T
authors.initials: T
authors.lastname: Prien
authors.forename: J
authors.initials: J
authors.lastname: Meyer
mesh_terms: D000767:Anesthesia, Epidural; D000818:Animals; D004305:Dose-Response Relationship, Drug; D006439:Hemodynamics / Q000187:drug effects; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology*; D009407:Nerve Block; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors*; D011897:Random Allocation; D012756:Sheep; D013564:Sympathetic Nervous System / Q000187:drug effects*; D014661:Vasoconstriction / Q000187:drug effects*
chemical_list: D019001:Nitric Oxide Synthase; D019331:NG-Nitroarginine Methyl Ester