Experimental Study On Effects Of Three Different Concentrations Of Hypertonic Saline On Early Lung Injury In Severely Scalded Rats

1.Objectives The present study is to investigate 200 mmol / L,400 mmol / L,600 mmol / L Na+at three concentrations of hypertonic saline(HS)and lactated Ringer's solution(LR)of the liquid supplement severely burned rats 8 hours after injury for resuscitation,The effects of various concentrations of hypertonic sodium chloride(HS)on lung injury in rats with severe scald were investigated from five aspects including serum sodium,inflammatory cytokines,oxidative stress,pathological morphology of lung tissue,and inflammatory signal transduction pathway.2.Materials and methods40 weighing 200-250 g common type of female SD rats were purchased resulting from Anhui Medical University Experimental Animal Center.After all rats numbers using randomly divided into five groups: sham group,the LR group,HS200 group,HS400 group,HS600 group.All rats were anaesthetized with chloral anesthesia,their back hairs were shaved,and the tail veins were placed with trocars.The rats in the sham injury group were treated without any treatment.The abdominal aortic blood and lung tissues were directly sacrificed after the injury.All rats in the scald group were given30% deep II° to III° scald water was applied to the back and the corresponding LR and HS were used for burn resuscitation after injury.Rats in the LR group and each HS group were sacrificed 8 hours after rehydration to take abdominal aortic blood and lung tissue.Part I: Effect of three different concentrations of hypertonic saline of 8 hours after injuryn serum serum sodium and inflammatory cytokines in rats after severe scald Take out a part of the five groups in rat plasma,the content of sodium ions in the plasma was measured by using an automatic biochemical analyzer.Plasma levels of TNF-?,IL-6 and IL-17 were measured by enzyme-linked immunosorbent assay(ELISA).Finally,the obtained data was statistically analyzed.Part II: Effects of hypertonic sodium salt solution at three different concentrations of 8 hours after injury on oxidative damage and lung morphology of lungs in severely scalded rats Take out a part of the lung tissues of the rats in the five groups.The contents of malondialdehyde(MDA)and superoxide dismutase(SOD)activity in the lung tissue were determined by colorimetry.The data were statistically analyzed.Lung tissue in10% formaldehyde fixation,the use of HE staining observed lung cell morphology and pathological changes.Part III: Effects of three different concentrations of hypertonic saline on the activation of p38 MAPK and ERK channels in lung tissue of severe scalded rats at 8hours after injury The lung tissues of five groups of rats cryopreserved in a low temperature refrigerator were taken out.Western blot was used to measure the phosphorylation ratios of p38 MAPK and ERK in lung tissues of each group and the data were analyzedstatistically.Result Part I: Serum sodium: At 8h post injury,serum sodium was significantly reduced in the LR group compared with the sham group.(P <0.01),while there was no significant difference among the three HS groups(P> 0.05).Compared with LR group,serum sodium was significantly elevated in the three HS groups(P <0.01).Compared with HS400 group,serum sodium in HS200 group and HS600 group increased significantly(P <0.01),but there was no significant difference in HS400 group and HS600 group(P>0.05).inflammatory cytokines:At 8h post injury,Compared with the sham group,the TNF-? levels were significantly higher than in the LR group and each HS group.(P<0.01);compared with LR group,TNF-?levels in three HS groups were significantly decreased(P <0.01);Compared with HS400 group,the TNF-? levels in HS200 group and HS600 group were significantly increased,while TNF-? levels in HS200 group and HS600 group were not significantly changed.(P> 0.05);IL-6 levels in LR group and three HS groups were significantly higher than those in sham group(P <0.01).Compared with LR group,IL-6 in HS200 group and HS400 group were significantly decreased(P <0.01),The HS600 group was not statistically significant(P>0.05).Compared with sham group,IL-17 levels were significantly higher than in the LR group and the various HS groups(P <0.01);Compared with LR group,IL-17 in three HS groups were significantly decreased(P <0.01),While the IL-17 was no significant difference between HS200 group,HS400 group and HS600 group(P> 0.05).Part II: At 8 h post injury,compared with sham operation group,the content of MDA in lung tissue of LR group and three HS groups increased obviously and SOD activity decreased obviously(P <0.01).Compared with the LR group,the MDA content in all HS groups was significantly lower and the SOD activity was significantly higher(P<0.01).Compared with the HS400 group,the MDA content in the HS200 group and the HS600 group increased significantly and the SOD activity decreased significantly(P<0.01)),The comparison between HS200 and HS600 groups is meaningless(P> 0.05).HE staining of lung tissue showed that in the LR group,pulmonary interstitial thickening,interstitial vascular congestion and neutrophil aggregation around the blood vessels were observed.The pathological changes in the lung tissue of the three HS groups were reduced to The histopathological changes of HS400 group were the smallest,which were almost the same as those of normal tissues.The pathological changes of HS400 group and HS600 group were similar.Part III: At 8h post injury,compared with sham group,the activity of p38 MAPK in the lungs of the LR group and each HS group was significantly increased,and the difference was statistically significant(P <0.01),compared with LR group,The p38 MAPK activities in HS200,HS400,and HS600 groups were significantly decreased(P<0.01),and the p38 MAPK activity in HS400 group was significantly decreased compared with HS200 group and HS600 group,There was no significant difference in p38 MAPK activity between HS200 and HS600 groups.(P> 0.05).The ERK activity was significantly increased in LR group and HS600 group compared with that in sham group(P <0.01).Compared with LR group,The ERK activity of HS200 group,HS400 group and HS600 group were significantly decreased(P <0.01),At the same time,the activity of ERK channels in HS200 group and HS400 group was significantly decreased compared with HS600 group(P <0.01),The ERK activity was no significant change between HS200 group and HS400 group.(P> 0.05).Conclusion(1)Burn resuscitation with 200 mmol / l,400 mmol / l,and 600 mmol / l HS can rapidly improve the early hyponatremia and regulates the imbalance of inflammatory response in severely scalded rats compared with LR recovery after injury.Inhibit the release of a large number of inflammatory cytokines in vivo,thereby reducing the inflammatory response,of which 400 mmol / l HS rehydration best.(2)Burn resuscitation with 200 mmol / l,400 mmol / l and 600 mmol / l HS could reduce the massive generation and alleviation of oxygen free radicals in the early post-injury lung tissue of severely scalded rats compared with LR treatment after injury The morphological and structural damage of lung tissue,of which 400 mmol / l HS treatment best.(3)Burn resuscitation with 200 mmol / l,400 mmol / l and 600 mmol / l HS can significantly inhibit the activation of p38 MAPK and ERK channels in the early stage lung tissue of severely scalded rats,And then reduce the body damage,of which400 mmol / l HS rehydration best.