Protective effects of early treatment with lipoic acid in LPS-induced lung injury in rats.
A lipopolysaccharide (LPS) stimulates the synthesis and releases several metabolites from phagocytes which can lead to an endotoxic shock characterized by multiple organ injury with the earliest to occur in the lungs. Among LPS-induced metabolites, reactive oxygen species are considered to play a crucial pathogenetic role in the lung damage. In this study, the effect of early administration of an antioxidant, alpha-lipoic acid (LA), on pulmonary lipid peroxidation, lung hydrogen peroxide (H(2)O(2)) concentration, and lung sulfhydryl group content was evaluated in rats with endotoxic shock induced by administration of LPS (Escherichia coli 026:B6, 30 mg/kg, i.v.). In addition, lung edema was assessed with wet-to-dry lung weight (W/D) ratio. Animals were treated intravenously with normal saline or LA 60 mg/kg or 100 mg/kg 30 min after LPS injection. After a 5 h observation, animals were killed and the lungs were isolated for measurements. Injection of LPS alone resulted in the development of shock and oxidative stress, the latter indicated by a significant increase in the lung thiobarbituric acid reacting substances (TBARS) and H(2)O(2) concentrations, and a decrease in the lung sulfhydryl group content. The increase in the W/D ratio after the LPS challenge indicated the development of lung edema in response to LPS. Administration of LA after the LPS challenge resulted in an increase in the sulfhydryl group content and a decrease in TBARS and H202 concentration in the lungs as compared with the LPS group. An insignificant decrease in the W/D ratio was observed in rats treated with either dose of LA. These results indicate that the LPS-induced oxidative lung injury in endotoxic rats can be attenuated by early treatment with LA. Administration of LA could be a useful adjunct to conventional approach in the management of septic shock.
Goraca
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Chair of Experimental and Clinical Physiology, Department of Cardiovacular Physiology, Medical University of Łódź, Poland. agoroca@zdn.am.lodz.pl
Józefowicz-Okonkwo
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D000704:Analysis of Variance; D000818:Animals; D000975:Antioxidants / Q000494:pharmacology / Q000627:therapeutic use; D001522:Behavior, Animal / Q000187:drug effects; D001831:Body Temperature / Q000187:drug effects; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D004305:Dose-Response Relationship, Drug; D006861:Hydrogen Peroxide / Q000378:metabolism; D007275:Injections, Intravenous; D015227:Lipid Peroxidation / Q000187:drug effects; D008070:Lipopolysaccharides / Q000008:administration & dosage / Q000633:toxicity*; D008168:Lung / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D008297:Male; D018384:Oxidative Stress / Q000187:drug effects; D011654:Pulmonary Edema / Q000139:chemically induced / Q000517:prevention & control*; D051381:Rats; D017208:Rats, Wistar; D013438:Sulfhydryl Compounds / Q000378:metabolism; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism; D008063:Thioctic Acid / Q000494:pharmacology* / Q000627:therapeutic use; D013997:Time Factors
D000975:Antioxidants; D008070:Lipopolysaccharides; D013438:Sulfhydryl Compounds; D017392:Thiobarbituric Acid Reactive Substances; D008063:Thioctic Acid; D006861:Hydrogen Peroxide