The Influence Of SNAC On Oxidation In Rats Infected By Pyocyanin

ObjectiveTo investigate the oxidative damage of rats infected by pyocyanin and itsmechanism,and further to discuss the effect of S-nitroso-N-acetylcysteine（SNAC）on rats after infected.Methods90rats were divided into three groups randomly, they were (1) the normalcontrol group: we gave the normal saline1ml/100g weight by peritonealinjection and rats were managed with0.2ml normal saline;(2) the model group:we gave the normal saline1ml/100g weight by peritoneal injection and infectedrats with0.2ml PCN (6×108CFU/ml), instilled bacteria into the lung via theendotracheal route directly after rats anesthetized;(3) the SNAC interruptedgroup: we gave SNAC (1ml/100g weight) for intervention before infected atonce, and the rest were the same as the model group. We killed rats afterinfected6h,18h,30h,48h,72h, respectively,and then collected the lung tissueand bronchoalveolar lavage for inspection; We made the pathological section oflung tissue, observed the general condition of rat, the morphology of lung tissue,calculation the mount of BALF cells and detected the contents of reactiveoxygen species (ROS) and malondialdehyde(MDA),superoxide dismutase(SOD) activity and the interleukin-8(IL-8) content using kits,and the albumencontent SOD were measured with Western blot. Results(1) The general observation: The rats of PCN group becamedepression,loss of appetite,chills,fever,dyspnea after infected6h, and they werethe most highlighted at30h; we executed the rats and observed the lung tissuesafter infected6,18and30,48,72h; the appearance of the lung was pink in therats of the control group,and there was no obvious changes; petechialhemorrhages was seen in the surface of lung after PCN infection6h,whileduring the18-72h we saw that the volume increased, the appearance of thelung was dark red and the surface was splinter hemorrhage;the lung tissues inSNAC lung were lighten than that in PCN group.(2)The histological morphologic of lung: We can see that the structure oflung tissue was clear,and there was no thickening and inflammatory cellinfiltration in alveoli septum; while the integrity of alveolar walls structure wasdestroyed, alveolar interval was thicken,and the lung tissue was with obvioushyperemia,edema, a large number of inflammatory cells infiltration in PCNgroup, and there was more obvious in30h; The inflammatory response, theintegrity of alveolar walls structure, hyperemia, edema and cells infiltration oflung were improved in SNAC group than that in PCN group.(3)The cells and neutrophils in BALF:The differences of cells and neutrophilof all rats after infected6,18,30,48,72h were significant(P <0.05);The cells andneutrophils in BALF of the PCN and SNAC group at each time point were moreincreasing than the control group;and they were less in SNAC group than thatin PCN group,and the difference was significant (P <0.05).(4)The results of determined by kits:The differences of the contents ofROS,SOD activity, IL-8content after rats infected6,18,30,48,72h by PCN weresignificant (P<0.05); the contents of ROS,MDA and the expression of IL-8inPCN and SNAC group at each time point were more than the control group,andthey were less in SNAC group than that in PCN group;and the SOD activity ofSNAC and PCN group was less than that of the control group,and it was more inSNAC group than that in PCN group (P <0.05).(5)The results of western blot:There was significant difference of the SOD protein after PCN infection6,18,30,48,72h(P <0.05);the SOD protein in PCNand SNAC group at each point time was less than that in the control group,and itwas more in SNAC group than that in PCN group (P <0.05),and it wassignificant in30h.Conclusions1. Pyocyanin-induced toxicity in rats is causally linked to oxidative stress;2. SNAC plays a protective role in oxidative damage of rats lung infected byPCN through ROS decreased.