| Objective:Establish the BPD(Bronchopulmonary dysplasia)animal model of SD rats to detect the related hyperoxic lung injury and the changes of inflammatory factors IL-8/CXCL8 and inflammatory signal pathway NF-κB in the BPD rat model,and give IL-8/CXCL8 receptors The antagonist G31P intervenes in the BPD rat model to explore the protective mechanism of G31P on BPD rats.method: Randomly select newborn SD rats,48 ? ? males and females are not limited,divided into 3 groups,each with 16 rats:(1)control group(Fi02=21%)(2)Hyperoxia control group(Fi02=60%),(3)Hyperoxia G31P treatment group(Fi02=60%).The hyperoxia control group was placed in a self-made airtight oxygen box,and the oxygen concentration was maintained at 60%.The hyperoxia G31P treatment group was placed in an oxygen box in the same environment as the hyperoxia group,and G31P was injected intraperitoneally with 500μg/kg once a day;the normal group and the hyperoxia group were intraperitoneally injected with the same dose of normal saline once a day.Observe the rat’s mental status,activity and eating status,and record the weight of the newborn rat.The lung tissues of neonatal rats were taken at 3d,7d,14 d,21d after birth,and the general morphology of the lung tissue was observed.Using HE staining and Masson staining methods,the pathological changes and the degree of fibrosis of the lung tissues were observed.At the same time,real-time RTPCR and Western Blot methods were used to detect the expression of CXCR1/CXCR2 and NF-κB at the protein and mRNA levels in the lung tissues of rats in each group.Result: 1.General situation: In the first three days of the experiment,there was no obvious difference in the general situation of the rats in each group.With the prolongation of hyperoxia time,there were obvious differences between the groups.The rats in the normal group were mentally active and breathed smoothly.,Eating well and gaining normal weight.On the 7th day of the experiment,the rats in the hyperoxia group responded moderately,with reduced voluntary activity,reduced food intake,and shortness of breath after leaving the oxygen environment,which can be relieved by resuming oxygen supply;on the 14 th day,the rats in the hyperoxia group responded poorly and reduced voluntary activities,Body hair is dull,and mild breathing difficulties appear when leaving the oxygen environment;on the 21 st day,the rats in the hyperoxia group are thin,lethargic,and have poor response.Breathing difficulties are aggravated when leaving the oxygen environment,and the skin of the nose wing is cyanotic,and the oxygen concentration in the environment can be the general changes in the lung tissues of each group were observed.The control group: The lung tissues of newborn SD rats are normal in volume,rosy in color,soft in texture,and good elasticity;hyperoxia group: The surface of the lungs of newborn SD rats exposed to hyperoxia for 3 days has darker color,and the elasticity is worse than that of the normal group.On the7 th day of hyperoxia The lungs of the newborn rats were congested and edema,scattered bleeding spots appeared on the surface of the lungs,and the texture was slightly tough;the lung tissues of the newborn rats after 14 days of hyperoxia exposure were paler and edema than the control group,and some lung lobes were hemorrhage,and the lung tissues were tougher;high oxygen exposure 21 In the day,both lungs were reduced in size,pale in color,and tough in texture;the general changes in the hyperoxia G31P group were significantly reduced in the higher oxygen group.2.HE staining: the alveolar structure of the normal group is intact,the alveolar appearance is uniform,and the number of alveoli is large;the number of alveoli in the hyperoxia control group is significantly reduced,the volume becomes larger and some are fused,the interval is thickened,the structure is disordered,and there are telangiectasias,and some There is infiltration of inflammatory cells.The pathological changes of the hyperoxia G31P treatment group were between the normal group and the hyperoxia group.3.Masson staining: Collagen deposition is rare in the normal control group,while in the hyperoxia control group at 3 days,there is no abnormal change in the experimental groups.On the 7th day,there is a small amount of collagen fiber deposition in the lung tissue;on the 21 st day,the lung tissue More collagen fiber deposition and lung tissue fibrosis can be seen;the collagen fiber deposition in the hyperoxia G31P treatment group is between the hyperoxia group and the normal group.4.The expression levels of C X C R 1 / C X C R 2 in mRNA and protein products in the lung tissues of the three groups of rats.On days 3,7,14,and 21,the mRNA level of CXCR1/CXCR2 in the lung tissue of the hyperoxia control group was significantly higher than that of the normal group and the G31P treatment group(P<0.05);the difference was the most on the 14 th day of the experiment on the protein expression product Significant(P<0.05),that is,the hyperoxia group was significantly higher than the normal group and the G31P treatment group.7.Comparison of the changes of NF-κB mRNA and protein products in the lung tissues of the three groups of rats.On days 3,7,14,and 21,NF-κB mRNA in the lung tissues of the hyperoxia group was significantly higher than that of the normal group and the hyperoxia G31P treatment group(P<0.05),while the protein expression level of the experimental rats in each group Significant difference appeared on the 14 th day(P<0.05).Conclusions:1.This study successfully established a rat BPD animal model;2.Compared with the hyperoxia control group,G31P can significantly improve the pathological changes of the lung tissue of BPD rats,indicating that it has a therapeutic effect on BPD rats;3.The mechanism of G31P in the treatment of BPD may inhibit NF-κB and reduce inflammation. |
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