title: Short-term (48 hours) intravenous serelaxin infusion has no effect on myogenic tone or vascular remodeling in rat mesenteric arteries.
abstract: Short-term IV sRLX (recombinant human relaxin-2) infusion enhances endothelium-dependent relaxation in mesenteric arteries. This is initially underpinned by increased NO followed by a transition to prostacyclin. The effects of short-term IV sRLX treatment on pressure-induced myogenic tone and vascular remodeling in these arteries are unknown. Therefore, we investigated the effects of sRLX infusion on pressure-induced myogenic tone and passive mechanical wall properties in mesenteric arteries.
  
  
  
  Mesenteric artery myogenic tone and passive mechanics were examined after 48-hours and 10-days infusion of sRLX. Potential mechanisms of action were assessed by pressure myography, qPCR, and Western blot analysis.
  
  
  
  Neither 48-hours nor 10-days sRLX treatment had significant effects on myogenic tone, passive arterial wall stiffness, volume compliance, or axial lengthening. However, in 48-hours sRLX -treated rats, incubation with the NO synthase blocker L-NAME significantly increased myogenic tone (P<.05 vs placebo), demonstrating an increased contribution of NO to the regulation of myogenic tone. eNOS dimerization, but not phosphorylation, was significantly upregulated in the arteries of sRLX -treated rats.
  
  
  
  In mesenteric arteries, 48-hours sRLX treatment upregulates the role of NO in the regulation of myogenic tone by enhancing eNOS dimerization, without altering overall myogenic tone or vascular remodeling.
authors.affiliation: School of BioSciences, The University of Melbourne, Parkville, Victoria, Australia.
authors.forename: Maria
authors.identifier: 0000-0001-9773-4972
authors.initials: M
authors.lastname: Jelinic
authors.affiliation: School of BioSciences, The University of Melbourne, Parkville, Victoria, Australia.
authors.forename: Chen Huei
authors.initials: CH
authors.lastname: Leo
authors.affiliation: School of BioSciences, The University of Melbourne, Parkville, Victoria, Australia.
authors.forename: Sarah A
authors.initials: SA
authors.lastname: Marshall
authors.affiliation: School of BioSciences, The University of Melbourne, Parkville, Victoria, Australia.
authors.forename: Sevvandi N
authors.initials: SN
authors.lastname: Senadheera
authors.affiliation: School of BioSciences, The University of Melbourne, Parkville, Victoria, Australia.
authors.forename: Laura J
authors.initials: LJ
authors.lastname: Parry
authors.affiliation: Department of Physiology, Monash University, Clayton, Victoria, Australia.|Monash Rural Health, Monash University, Churchill, Victoria, Australia.
authors.forename: Marianne
authors.initials: M
authors.lastname: Tare
mesh_terms: D000818:Animals; D008638:Mesenteric Arteries / Q000187:drug effects*; D009129:Muscle Tonus / Q000187:drug effects*; D009569:Nitric Oxide / Q000502:physiology; D052250:Nitric Oxide Synthase Type III / Q000378:metabolism; D055503:Protein Multimerization; D051381:Rats; D011994:Recombinant Proteins / Q000008:administration & dosage / Q000494:pharmacology; D012065:Relaxin / Q000008:administration & dosage / Q000494:pharmacology*; D013997:Time Factors; D066253:Vascular Remodeling / Q000187:drug effects*
chemical_list: D011994:Recombinant Proteins; C577649:serelaxin protein, human; D009569:Nitric Oxide; D012065:Relaxin; D052250:Nitric Oxide Synthase Type III; C496316:Nos3 protein, rat
keywords: myogenic tone; nitric oxide; relaxin; vascular stiffness