title: Endothelium-dependent and -independent relaxation in the forelimb and hindlimb vasculatures of swine.
abstract: Limb differences in endothelial function exist between arm and leg vasculatures of humans. The current investigation tested the hypothesis that forelimb and hindlimb vasorelaxation are similar in the absence of limb differences in blood pressure. Conduit arteries (brachials/femorals) and second order arterioles were harvested from 22 miniature Yucatan swine. In vitro assessment of vasorelaxation was determined by administering increasing doses of bradykinin (BK), acetylcholine (ACh), and sodium nitroprusside (SNP). The role of the nitric oxide synthase (NOS) and cyclooxygenase (COX) pathways was assessed in conduit arteries but not resistance arterioles through L-NAME (300 microM) and INDO (5 microM) incubation, respectively. The relaxation responses to BK and ACh were similar in brachial and femoral arteries. SNP relaxation response was greater in the brachial compared to femoral arteries. There were also no significant differences in the relaxation responses of second order arterioles of the forelimb and hindlimb to BK, ACh, and SNP. Incubation of conduit arterial rings in L-NAME produced a greater reduction in BK and ACh relaxation in the brachial (approximately 25%) compared to femoral (approximately 13%) arterial rings. The current results of this investigation suggest that the forelimb and hindlimb vasculatures of swine have relatively similar vasorelaxation responses to both endothelium-dependent and -independent vasodilators.
authors.affiliation: Department of Biomedical Science, University of Missouri, Columbia, Missouri, United States. newcomers@missouri.edu
authors.forename: Sean C
authors.initials: SC
authors.lastname: Newcomer
authors.forename: Jessica C
authors.initials: JC
authors.lastname: Taylor
authors.forename: Douglas K
authors.initials: DK
authors.lastname: Bowles
authors.forename: M Harold
authors.initials: MH
authors.lastname: Laughlin
mesh_terms: D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D001160:Arterioles / Q000502:physiology; D001783:Blood Flow Velocity; D001794:Blood Pressure; D001916:Brachial Artery / Q000187:drug effects / Q000201:enzymology / Q000502:physiology*; D001920:Bradykinin / Q000494:pharmacology; D016861:Cyclooxygenase Inhibitors / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004730:Endothelium, Vascular / Q000187:drug effects / Q000502:physiology*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005260:Female; D005263:Femoral Artery / Q000187:drug effects / Q000201:enzymology / Q000502:physiology*; D005552:Forelimb / Q000098:blood supply*; D006614:Hindlimb / Q000098:blood supply*; D066298:In Vitro Techniques; D007213:Indomethacin / Q000494:pharmacology; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D009569:Nitric Oxide / Q000378:metabolism; D052250:Nitric Oxide Synthase Type III / Q000037:antagonists & inhibitors / Q000378:metabolism; D009599:Nitroprusside / Q000494:pharmacology; D011451:Prostaglandin-Endoperoxide Synthases / Q000378:metabolism; D011453:Prostaglandins / Q000378:metabolism; D012039:Regional Blood Flow; D012107:Research Design; D013552:Swine; D013556:Swine, Miniature; D014664:Vasodilation / Q000187:drug effects; D014665:Vasodilator Agents / Q000494:pharmacology
chemical_list: D016861:Cyclooxygenase Inhibitors; D004791:Enzyme Inhibitors; D011453:Prostaglandins; D014665:Vasodilator Agents; D009599:Nitroprusside; D009569:Nitric Oxide; D052250:Nitric Oxide Synthase Type III; D011451:Prostaglandin-Endoperoxide Synthases; D000109:Acetylcholine; D001920:Bradykinin; D019331:NG-Nitroarginine Methyl Ester; D007213:Indomethacin