Lipoic acid decreases exhaled nitric oxide concentrations in anesthetized endotoxemic rats.
We recently demonstrated that lipoic acid suppresses endotoxin-stimulated expression of inducible nitric oxide synthase and nitric oxide production in mouse macrophages. In this study, we tested whether lipoic acid suppresses these inflammatory mediators in the lungs of rats. Rats were assigned to receive either no special treatment, endotoxin alone, or pretreatment with lipoic acid followed by endotoxin. After anesthetizing the rats and injecting them intraperitoneally with lipoic acid (100 mg/kg) at 4 h and again at 1 h before treatment, the rats then received either endotoxin (0.01 mg/kg) or its vehicle solution. Exhaled gas was sampled every 15 min and concentrations of nitric oxide in the samples were measured using a chemiluminescence analyzer. After 150 min of exposure to endotoxin, the lungs were harvested and snap-frozen in liquid nitrogen for subsequent analysis. Lipoic acid attenuated endotoxin-induced increases in exhaled nitric oxide concentrations (P<0.001) and iNOS (P<0.05). These findings support the hypothesis that lipoic acid inhibits endotoxin-stimulated formation of intrapulmonary nitric oxide.
De Marco
Vincent G
VG
Department of Child Health, University of Missouri, USA.
Bosanquet
James P
JP
Rawlani
Vinay R
VR
Skimming
Jeffrey W
JW
D000758:Anesthesia; D000818:Animals; D001784:Blood Gas Analysis; D015153:Blotting, Western; D004305:Dose-Response Relationship, Drug; D004591:Electrophoresis, Polyacrylamide Gel; D024202:Electrophoretic Mobility Shift Assay; D019446:Endotoxemia / Q000201:enzymology / Q000378:metabolism*; D008168:Lung / Q000187:drug effects / Q000201:enzymology; D008297:Male; D016328:NF-kappa B / Q000378:metabolism; D009569:Nitric Oxide / Q000378:metabolism*; D052247:Nitric Oxide Synthase Type II / Q000096:biosynthesis; D009687:Nuclear Proteins / Q000302:isolation & purification; D051381:Rats; D017207:Rats, Sprague-Dawley; D012996:Solutions; D008063:Thioctic Acid / Q000494:pharmacology*
D016328:NF-kappa B; D009687:Nuclear Proteins; D012996:Solutions; D009569:Nitric Oxide; D008063:Thioctic Acid; D052247:Nitric Oxide Synthase Type II