Selective inhibition of sympathetic nerve-mediated contraction by L-arginine in lipopolysaccharide-treated tail artery of rats.
The effects of L-arginine on the adrenergic responses to either electrical transmural stimulation or phenylephrine were studied in isolated endothelium-denuded strips of rat tail arteries treated with lipopolysaccharide for 6 h in vitro. L-arginine did not relax the strips precontracted by phenylephrine. However, the adrenergic contractions induced by electrical transmural stimulation were significantly inhibited by the addition of L-arginine. This inhibitory effect was reversed by NG-nitro-L-arginine (a nitric oxide synthase inhibitor) or methylene blue (a soluble guanylate cyclase inhibitor) but was not affected by hemoglobin (a scavenger of nitric oxide). These results indicate that the adrenergic neurogenic contractions may be directly modulated by nitric oxide derived from the sympathetic nerves and/or neighboring cells in the lipopolysaccharide-treated rat tail arteries, and the nitric oxide production may be associated with the reduction of sympathetic tone in sepsis.
Takakura
K
K
Department of Anesthesiology and Reanimatology, Fukui Medical School, Japan.
Goto
Y
Y
Kigoshi
S
S
Muramatsu
I
I
D000594:Amino Acid Oxidoreductases / Q000096:biosynthesis; D000818:Animals; D001120:Arginine / Q000494:pharmacology*; D004558:Electric Stimulation; D066298:In Vitro Techniques; D008070:Lipopolysaccharides / Q000494:pharmacology*; D008297:Male; D009569:Nitric Oxide / Q000502:physiology*; D019001:Nitric Oxide Synthase; D051381:Rats; D017208:Rats, Wistar; D013564:Sympathetic Nervous System / Q000502:physiology*; D013623:Tail / Q000098:blood supply; D014661:Vasoconstriction / Q000187:drug effects*
D008070:Lipopolysaccharides; D009569:Nitric Oxide; D001120:Arginine; D019001:Nitric Oxide Synthase; D000594:Amino Acid Oxidoreductases