The Effecting Of SP-A And SP-B In Lipoic Acid On Acute Paraquat Poisoning

Objective:Observed the concentration of SP-A / B in pulmonary surfactant in metabolic antioxidant lipoic acid on acute lung injury / acute respiratory distress syndrome caused by acute paraquat poisoning,and whether its influence about with the TNF-a? Discussion the protective-mechanisms in lipoic acid on acute lung injury.Methods :Selecting Healthy male Sprage-Dawley 66 rats, and they were randomly divided into 3 groups: control group (NS), paraquat poisoning group (PQ), paraquat + lipoic acid treatment group (LA). For NS Group 6 rats,for PQ group and LA group the 30 rats separately selected after the model was successfully, then subdivided five sub-groups, 3h, 6h, 12h, 24h, 48h subgroups, each subgroup 6 rats. NS group was given 0.9% sodium chloride Intraperitoneal injection; PQ grou was given PQ 25mg/kg intraperitoneal injection; LA group was given intraperitoneal injection of PQ 25mg/kg, while giving LA 100mg/kg tail vein injection. The lung tissue the Same part of rat selected ,do HE staining, histological changes observed under light microscope; take the same another part of lung tissue determination SOD, MDA levels; from rat tail vein of non-anticoagulant whole blood 0.8ml for determinating the TNF-a level; collect the total RNA of the lung tissue, with the Rt-PCR method to measure SP-A, SP-B mRNA levels.Results:①HE staining showed that the PQ group with time increase interval between the lung damage increase, the blood capillary of pulmonary alveolar wall expand hyperemia. trachea and blood vessels around the different degrees of edema, in lung tissue, the inflammatory cells with lots of neutrophils mainly Infiltration. But the LA group after the intervention treatment, the above same point of PQ group ,the lung injury lighten more than the PQ group.②SOD vigors: LA group and the PQ the same point of the comparison group were higher, P <0.01 was statistically significant; LA group at each time point were lower compared with the NS group, P <0.05 was statistically significant. MDA levels: LA group and the PQ the same point of the comparison group were lower, P <0.01 was statistically significant; LA group at each time point compared with the NS groups were higher, for 6h, 12h, 24h, 48h time point but 3h time point , P <0.05 was statistically significant.③TNF-a levels: LA group and the PQ the same point of the comparison group were lower, P <0.01 was statistically significant; LA group at each time point compared with the NS groups were higher, P <0.05 was statistically significant④SP-A, SP-B mRNA expression: LA group and the PQ group was significantly more than the same time point, P <0.01 was statistically significant; LA group at each time point compared with the NS group were low, P <0.05 was statistically significant;Conclusions:Lipoic acid in acute paraquat poisoning can reduce lung tissue damage, which may be directly regulated by the levels of tumor necrosis factor, to indirectly affect the content of pulmonary surfactant, thereby reducing pulmonary edema and improving lung compliance, then protecting the lungs organization.