title: Nitric oxide synthesis inhibition does not improve the hemodynamic response to hemorrhagic shock in dehydrated conscious swine.
abstract: Nitric oxide (NO) may influence the hemodynamic response to hemorrhage. To test this hypothesis, the NO synthesis inhibitor N omega-nitro-L-arginine methyl ester (L-NAME) was administered to conscious, dehydrated swine during a 37% blood volume hemorrhage and a 180 min recovery period without fluid resuscitation. L-NAME (.75 mg/kg bolus plus constant infusion of .75 mg/kg/h) was given via a central intravenous catheter during the bleed. The selectivity and specificity of L-NAME as a NO synthesis inhibitor in pigs was validated in pilot studies. The present study shows that inhibition of NO synthesis with L-NAME had no significant effect on the major hemodynamic parameters during and after hemorrhage when compared to dehydrated and euhydrated control groups. Only stroke volume and A-VO2 were significantly different from controls. Mortality was 83% for the L-NAME group and 44% for controls at 180 min of recovery (NS). The results suggest that NO synthesis inhibition provides no hemodynamic benefit during hemorrhage in dehydrated, conscious swine.
authors.affiliation: Department of Pathology, University of California-San Diego 92093, USA.
authors.forename: I P
authors.initials: IP
authors.lastname: Brown
authors.forename: R L
authors.initials: RL
authors.lastname: Williams
authors.forename: M D
authors.initials: MD
authors.lastname: McKirnan
authors.forename: U R
authors.initials: UR
authors.lastname: Limjoco
authors.forename: C G
authors.initials: CG
authors.lastname: Gray
mesh_terms: D000818:Animals; D001120:Arginine / Q000031:analogs & derivatives / Q000494:pharmacology; D003681:Dehydration; D006439:Hemodynamics; D019331:NG-Nitroarginine Methyl Ester; D009569:Nitric Oxide / Q000096:biosynthesis*; D012771:Shock, Hemorrhagic / Q000378:metabolism / Q000503:physiopathology*; D013552:Swine
chemical_list: D009569:Nitric Oxide; D001120:Arginine; D019331:NG-Nitroarginine Methyl Ester