Low dose of lipopolysaccharide induces a delayed enhanced nitric oxide-mediated relaxation in rat aorta.
Delayed effect on vascular reactivity of isolated aorta was studied after injection of a single low dose of lipopolysaccharide (0.5 mg/kg i.p.). The maximal vascular effect was observed 72 h after lipopolysaccharide administration with an increase in maximal endothelium-dependent relaxing response to acetylcholine and parallelly a decrease in contractile response to phenylephrine. The change in contractile response was nullified by endothelium removal as well by in vitro aortic rings incubation with N(omega)-monomethyl-L-arginine but not with indomethacin. A low dose of lipopolysaccharide induces a delayed enhanced nitric oxide-mediated vascular relaxation which could contribute to its delayed anti-ischemic properties in ischemic tolerance phenomenon.
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Laboratoire de Pharmacologie, Faculté de Médecine, Lille, France.
Bordet
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Robin
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Puisieux
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F
Vallet
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Dupuis
B
B
D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000494:pharmacology; D001013:Aorta, Thoracic / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D004357:Drug Synergism; D066298:In Vitro Techniques; D007213:Indomethacin / Q000494:pharmacology; D008070:Lipopolysaccharides / Q000494:pharmacology*; D008297:Male; D009126:Muscle Relaxation / Q000187:drug effects*; D009131:Muscle, Smooth, Vascular / Q000187:drug effects*; D009569:Nitric Oxide / Q000378:metabolism / Q000494:pharmacology*; D010656:Phenylephrine / Q000494:pharmacology; D051381:Rats; D013997:Time Factors; D014662:Vasoconstrictor Agents / Q000494:pharmacology; D014665:Vasodilator Agents / Q000494:pharmacology; D019323:omega-N-Methylarginine / Q000494:pharmacology
D000894:Anti-Inflammatory Agents, Non-Steroidal; D008070:Lipopolysaccharides; D014662:Vasoconstrictor Agents; D014665:Vasodilator Agents; D010656:Phenylephrine; D019323:omega-N-Methylarginine; D009569:Nitric Oxide; D000109:Acetylcholine; D007213:Indomethacin