Research On The Relationship Between Inhaled PM2.5 And Chronic Obstructive Pulmonary Disease And Acute Exacerbation

Objective:To establish a model of chronic obstructive pulmonary disease(COPD)by inhaled PM2.5.To observe the effects of different concentrations of PM2.5 on the general situation and pulmonary function of rats with chronic obstructive pulmonary disease(COPD),and to explore the differences in response to PM2.5 exposure in rats under different pathological conditions.To provide experimental data for PM2.5 epidemiological investigation on the impact of acute exacerbation and prognosis of COPD in people with acute respiratory syndrome(COPD),and provide ideas for elucidating the pathological mechanism of PM2.5-induced acute exacerbation of COPD.Methods:(1)Construction and identification of COPD model: 50 healthy Wistar rats of 8 weeks old were selected as the research object.The random number table was used to divide the Wistar rats into 5 groups for COPD model construction.Group A was treated with intratracheal instillation of lipopolysaccharide combined with fumigation,group B was treated with smoke alone,Group C received intratracheal instillation of lipopolysaccharide combined with smoked PM2.5 method,and group D smoked PM2.5 alone.Group E served as healthy control group.The general condition of the rats was observed and the peripheral blood count,bronchoalveolar lavage fluid(BALF)cell count and classification,lung function was detected.The mean lined interval(MLI)and mean alveolar number(MAN)of rats were measured to evaluate the modeling effect.(2)Differences in response to pathological conditions in rats exposed to different concentrations of PM2.5:50 COPD rats were selected as study subjects,and randomly divided into 5 groups by random number table method.N group as a normal control group,P1 group placed in 50μg / m3 PM2.5 environment,P2 group placed in 100μg / m3 PM2.5 environment,P3 group placed in 200μg / m3 PM2.5 environment,P4 group placed in 500μg /m3 PM2.5 environment.The general conditions of rats were observed,and the peripheral blood routine,bronchoalveolar lavage fluid(BALF)cell count and classification,lung function were detected.The mean lined interval(MLI)and mean alveolar number(MAN)of rats were measured to evaluate the modeling effect.Results:(1)(1)General situation of rats: Compared with normal control rats in group E,rats in groups A,B,C,and D all showed decreased and decreased activities.There was no significant difference in the body weight of rats in each group.(2)Peripheral blood,bronchoalveolar lavage fluid(BALF)cell count and classification: Compared with normal control group E,the white blood cell count,erythrocyte distribution width and hematocrit of group A,group B,group C and group D tended to increase to some extent.Compared with group E,P <0.05,the difference was statistically significant;The total number of cells,percentage of neutrophils and percentage of lymphocytes in group A,group B,group C and group D were significantly increased,the percentage of macrophages was significantly decreased,compared with group E,P <0.05,difference has statistical significant;(3)Mean lined interval(MLI)and mean alveolar number(MAN)in rats: Compared with normal healthy control group E,the mean liner interval of group A,group B,group C and group D were significantly increased,the average alveolar number was significantly decreased,compared with group E,P <0.05,the difference has statistical significant.(4)Pulmonary function: PEF,FVC,FEV0.2 and FEV0.2 / FVC in group A,group B,group C and group D were significantly decreased compared with those in group E Comparison,P <0.05,the difference was statistically significant.(2)(1)General situation in rats: Compared with the normal control group,the rats in P1,P2,P3 and P4 groups showed decreased and decreased activity.There was no significant difference in the body weight of rats in each group.(2)Peripheral blood,bronchoalveolar lavage fluid(BALF)cell count and classification: Compared with the blank control group N,P1,P2 group rat macrophages accounted for slightly lower,other routine blood index showed a trend of slight rise.P3 and P4 group except the rat macrophages percentage decreased obviously,other blood routine indexes showed a trend of increased significantly.The higher the concentration of PM2.5,the more the white blood cell count,the distribution width of red blood cells,the hematocrit,the total number of cells,the percentage of neutrophils and the percentage of lymphocytes in each group increased significantly,and the percentage of macrophages decreased significantly.Compared with the blank control group N,P1,P2 group P > 0.05,there was no statistically significant difference,P3,P4 group P < 0.05,the difference was statistically significant;(3)Pulmonary function: Compared with the blank control group N,P1,P2 group rats PEF,FVC,FEV0.2 and FEV0.2 / FVC slightly lower,P3,P4 group rats PEF,FVC,FEV0.2 and FEV0.2 / FVC dropped significantly.The higher the concentration of PM2.5,PEF,FEV0.2 and FEV0.2 / FVC decreased significantly.Compared with the blank control group N,P1,P2 group P > 0.05,there was no statistically significant difference,P3,P4 group P < 0.05,the difference is statistically significant;(4)The mean lined interval(MLI)and mean alveolar number(MAN)in rats:Compared with the blank control group N,P1,P2 group rats average lined with slight increase,the average number of alveolar mild decrease,P3,P4 group rats average lined with interval are increased,the average number of alveolar decreased significantly.The higher the concentration of PM2.5,the more significant increase in the average liner interval in rats,the more significant reduction in the average number of alveoli.Compared with the blank control group N,P1,P2 group P > 0.05,there was no statistically significant difference,P3,P4 group P < 0.05,the difference is statistically significant.Conclusion:(1)PM2.5 can effectively establish the chronic obstructive pulmonary disease model.(2)The pathological state of chronic obstructive pulmonary disease model rats established by different concentrations of PM2.5 exposure have some differences.With the increase of the concentration of PM2.5,the pathological reaction in rats increased;(3)PM2.5 exposure and chronic obstructive pulmonary disease and acute exacerbations are closely related.