Endothelium-dependent vasodilation in response to Pseudomonas aeruginosa lipopolysaccharide: an in vitro study on canine arteries. Braz J Med Biol Res 1998 Oct;31(10):1329-34
Date
01/07/1999Pubmed ID
9876305DOI
10.1590/s0100-879x1998001000014Scopus ID
2-s2.0-0031727111 (requires institutional sign-in at Scopus site) 5 CitationsAbstract
Early systemic arterial hypotension is a common clinical feature of Pseudomonas septicemia. To determine if Pseudomonas aeruginosa endotoxin induces the release of endothelium-derived nitric oxide (EDNO), an endogenous nitrovasodilator, segments of canine femoral, renal, hepatic, superior mesenteric, and left circumflex coronary arteries were suspended in organ chambers (physiological salt solution, 95% O2/5% CO2, pH 7.4, 37 degrees C) to measure isometric force. In arterial segments contracted with 2 microM prostaglandin F2 alpha, Pseudomonas endotoxin (lipopolysaccharide (LPS) serotype 10(Habs) from Pseudomonas aeruginosa (0.05 to 0.50 mg/ml) induced concentration-dependent relaxation of segments with endothelium (P < 0.05) but no significant change in tension of arteries without endothelium. Endothelium-dependent relaxation in response to Pseudomonas LPS occurred in the presence of 1 microM indomethacin, but could be blocked in the coronary artery with 10 microM NG-monomethyl-L-arginine (L-NMMA), a competitive inhibitor of nitric oxide synthesis from L-arginine. The inhibitory effect of L-NMMA on LPS-mediated vasorelaxation of the coronary artery could be reversed by exogenous 100 microM L-arginine but not by 100 microM D-arginine. These experiments indicate that Pseudomonas endotoxin induces synthesis of nitric oxide from L-arginine by the vascular endothelium. LPS-mediated production of EDNO by the endothelium, possibly through the action of constitutive nitric oxide synthase (NOSc), may decrease systemic vascular resistance and may be the mechanism of early hypotension characteristic of Pseudomonas septicemia.
Author List
Evora PR, Ekin S, Pearson PJ, Schaff HVAuthor
Paul Joseph Pearson MD, PhD Chief, Professor in the Surgery department at Medical College of WisconsinMESH terms used to index this publication - Major topics in bold
AnimalsCoronary Vessels
Dogs
Enzyme Inhibitors
Female
Hypotension
In Vitro Techniques
Lipopolysaccharides
Male
Nitric Oxide
Nitric Oxide Synthase
Pseudomonas aeruginosa
Sepsis
Vasodilation
Vasodilator Agents
omega-N-Methylarginine