Short-term exposure to lipopolysaccharide is associated with microvascular contractile dysfunction in vivo.
The purpose of this study was to determine whether short-term exposure of resistance arterioles to lipopolysaccharide in situ is associated with changes in vasomotor tone. Using intravital microscopy, we found that suffusion of Escherichia coli lipopolysaccharide (3 micrograms/ml) over hamster cheek pouch arterioles for 1 h was associated with a significant immediate biphasic response: vasoconstriction followed by vasodilation (p < 0.05). The former was attenuated by indomethacin, and the latter by SK&F 108566, a selective, non-peptide angiotension II receptor antagonist (p < 0.05). The nitric oxide synthase inhibitor, NG-L-nitro arginine, had no significant effects on lipopolysaccharide-induced responses. Allopurinol, a scavenger of reactive oxygen species, significantly attenuated lipopolysaccharide-induced vasodilation. Acetylcholine- and nitroglycerin-induced vasodilation were significantly potentiated after lipopolysaccharide. These responses were recorded in the absence of any significant changes in systemic arterial blood pressure. Collectively, these data suggest that short-term exposure of the peripheral microcirculation to lipopolysaccharide in situ is associated with an ischemia-reperfusion-like injury. These changes may contribute to end organ failure observed several hours after exposure to lipopolysaccharide.
Gao
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Department of Medicine, University of Illinois at Chicago 60612-7323, USA.
Suzuki
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Olopade
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Rubinstein
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D000179:Acrylates / Q000494:pharmacology; D000493:Allopurinol / Q000494:pharmacology; D000818:Animals; D000959:Antihypertensive Agents / Q000494:pharmacology; D001120:Arginine / Q000031:analogs & derivatives / Q000494:pharmacology; D001160:Arterioles / Q000187:drug effects* / Q000503:physiopathology; D002610:Cheek / Q000098:blood supply; D006224:Cricetinae; D007093:Imidazoles / Q000494:pharmacology; D007213:Indomethacin / Q000494:pharmacology; D008070:Lipopolysaccharides / Q000494:pharmacology*; D008297:Male; D008647:Mesocricetus; D019335:Nitroarginine; D013876:Thiophenes; D014661:Vasoconstriction / Q000187:drug effects*; D014664:Vasodilation / Q000187:drug effects
D000179:Acrylates; D000959:Antihypertensive Agents; D007093:Imidazoles; D008070:Lipopolysaccharides; D013876:Thiophenes; D019335:Nitroarginine; C068373:eprosartan; D000493:Allopurinol; D001120:Arginine; D007213:Indomethacin