RESUMEN
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.
Asunto(s)
Lipopolisacáridos/toxicidad , Pulmón/efectos de los fármacos , Edema Pulmonar/prevención & control , Ácido Tióctico/farmacología , Análisis de Varianza , Animales , Antioxidantes/farmacología , Antioxidantes/uso terapéutico , Conducta Animal/efectos de los fármacos , Temperatura Corporal/efectos de los fármacos , Cromatografía Líquida de Alta Presión/métodos , Relación Dosis-Respuesta a Droga , Peróxido de Hidrógeno/metabolismo , Inyecciones Intravenosas , Peroxidación de Lípido/efectos de los fármacos , Lipopolisacáridos/administración & dosificación , Pulmón/metabolismo , Pulmón/patología , Masculino , Estrés Oxidativo/efectos de los fármacos , Edema Pulmonar/inducido químicamente , Ratas , Ratas Wistar , Compuestos de Sulfhidrilo/metabolismo , Sustancias Reactivas al Ácido Tiobarbitúrico/metabolismo , Ácido Tióctico/uso terapéutico , Factores de TiempoRESUMEN
OBJECTIVE: Systemic sclerosis (SSc) is accompanied by oxidative stress that in turn may accelerate endothelium degeneration and thus disease progression. We tested whether phagocytes from SSc patients release more reactive oxygen species (ROS) and whether this release correlates with some clinical parameters. METHODS: ROS production by blood phagocytes was measured with the luminol enhanced whole blood chemiluminescence (CL). Resting and N-formyl-methionyl-leucyl-phenylalanine -induced CL (fMLP-induced CL) was measured in 30 patients with SSc and 30 healthy controls matched as to age, sex, and level of cigarette smoking. RESULTS: Resting CL and fMLP-induced CL calculated per 10(4) phagocytes present in the assayed blood sample were higher in patients with systemic sclerosis than in healthy controls (median; range, 0.88; 0.47-1.39 vs. 0.73; 0.13-1.07 aU/10(4)p and 621; 293-3522 vs. 411; 289-810 aUxs/10(4)p, p<0.02). Patients treated with cyclophosphamide and/or prednisone for 11; 3-168 months did not differ in respect to CL from those that never received the medications. Similarly, no significant differences were found between patients with limited and diffuse SSc. Resting CL correlated (p<0.05) with clinically manifested interstitial lung disease (r=0.59), single breath carbon monoxide diffusing capacity (r= -0.56) and serum autoantibodies titre (r= 0.43). CONCLUSIONS: Blood phagocytes from patients with systemic sclerosis, especially from those with interstitial lung disease, generate elevated amounts of ROS as assessed with CL. This confirms the presence of systemic oxidative stress in SSc patients.