| Objective:Burn-blast combined injury is burns and defense two separate injury factors superposition in the body at the same time a compound damage form, its high mortality, illness weight, therefore clinical problems to be solved.Acute lung injury /acute respiratory distress syndrome is burned at burn-blast combined injury is one of the main causes of early death. Alveolar surface active substances(Pulmonary surfactant, PS) is secreted by alveolar type II epithelial cells of a kind of lipoprotein, with lower alveolar surface tension, maintain alveolar stability, prevent pulmonary edema, improve oxygenation.This experiment through the establishment of simulated real burn-blast combined injury model of rats, combined with the application of exogenous alveolar surface active substances, discusses its burn-blast combined injury of acute lung injury and provide experimental basis for clinical treatment of acute lung injury and theoretical basis.Methods:Selected 300 male SD rats, severe burn-blast combined injury model is established, by using the stochastic indicator method is divided into sham injury(S) group, the burn-blast combined injury treatment group(T) and control group(C).Main body experiment in each group before injuries 0 h and 6 h, 24 h, 48 h, 72 h after injury when a total of five observation point to observe, portable blood gas analyzer line of blood gas analysis were used to detect; Application of rat lung function instrument determination of rat lung function; By immune histochemical method to detect lung tissue myeloperoxidase, myeloperoxidase expression; Lung tissue pathology observation its morphological changes; The changes of TEM to observe the ultrastructure of lung tissue; Change in Western Blot method lung surface active substance binding protein A.Results:1. Change in boold gas analysis: T group PaO2 obviously higher than the C group at the each timepoint(P<0.05). T group Pa CO2 was lower than that of C group(P<0.05). T groups LAC was higher than that of C groups(P<0.05). 2. Change in lung function: Deep inspiratory capacity, tissue elasticity,central airway2. Change in lung function: Deep inspiratory capacity, tissue elasticity,central airway resistance, lung compliance, treatment group was significantly better than control group at 24 h(P<0.05). And it was no statistically significant difference(P>0.05).3. Change in MPO: T groups and C groups lung tissue MPO were higher than S groups. C groups lung tissue MPO higher than T groups, and B groups have a high degree of infiltration.4. Change in Pathological: At the timepoint 24 h of C groups lung tissue mainly for local alveolar structure, alveolar cavities and disappeared, substantial change, hyperplasia of fibrous tissue cells, plasma cells, lymphocytes, and neutrophil infiltration, there are have a pace of alveolars, alveolar epithelial cells fall off. alveolar interval swelling, bleeding, swelling in the bronchial epithelium, progressive increase of pulmonary hemorrhage and pulmonary edema,is the most serious. T groups were obviously better than C groups, which the post of alveolar cavity structure, neutrophil infiltration, lymphocytes, plasma cells, edema.5. Change in TEM: S groups were the normal lung tissue ultrastructure, AEC â…¡ visible nucleus, chromatin evenly, nuclear membrane boundary is clear. Cell membrane surface have whole of microvilli, cytoplasmic contains many organelles, and numerous lamellar corpuscle, endoplasmic reticulum and mitochondria. AEC â…¡ series of significant changes at the T groups and C groups. At the timepoint of 6 h T groups were with neutrophil infiltration, and lamellar corpuscle emptying relatively less than C groups. At the timepoint of 24 h T groups compared with C groups were less inflammatory cells and lamellar corpuscle density increased, the volume is uniform, round nucleolus arrangement. At the timepoint of 48 h T groups were better than C groups which alveolar cavity structure, lamellar corpuscle emptying, have not huge lamellar corpuscle. At the timepoint of 72 h P groups of lamellar corpuscle slightly increase, have not huge lamellar corpuscle.6. Change in alveolar epithelial cells of the TUNEL: At the timepoint of 6h, T group positive rate is 0.156,and C group is 0.410; At the timepoint of 24 h,T group positive rate is 0.129, and C group is 0.340; At the timepoint of 48 h, T group positive rate is 0.105, and C group is 0.307; At the timepoint of 72 h, T group positive rate is 0.110, and C group is 0.316. T group positive rate less than C group.7. Change in Western Blot: SP-A of T group and C group significantly lower than the sham groups from the timepoint of 6h. Two groups compare, P group significantly higher than B group(P>0.05).Conclusion: Exogenous pulmonary surfactant can improve oxygenation and alleviate pulmonary edema and pulmonary capillary membrane permeability of rats with severe burn blast combined injury. |
PDF Full Text Request