Effect Of Aspirin On Elastase-induced Emphysema In Mice

Chapter 1 Lung emphysema modeling in miceObjective:To investigate the appropriate concentration of elastase in modeling emphysema in mice.Methods:9 SPF male C57 mice with body weight(19-21)g were randomly divided into 3 groups.Mice in different groups were injected separately with solutions containing different concentrations of elastase(2.0u?3.0u?4.0u)per 20g body weight into the trachea once a week for 4 times in total,during which the body weight of the mice was recorded.After 4 weeks,bilateral whole lungs were taken for routine HE staining.Results:Three groups have different survival situation.Group A&B were all survival while there was only one left in group C.The body weight of group A or B is steady,but there was a situation that the body weight of the mice in group C declined rapidly after the second week and even caused two death at the third week during the modeling period.There were emphysema changes in all the lung sections,and with the increase of elastase concentration,the morphological structure destruction of the alveolar septum increased,and the coalescing between different alveoli increased severely.Conclusion:4-week elastase-induced emphysema model in mice successfully.To ensure the survival rate as much as possible,solution with an elastase concentration of 3.0u per 20g body weight per time is most suitable to induce typical emphysema in mice.Chapter 2 Effect of aspirin on emphysema induced by elastase in miceObjective:To investigate the effect of aspirin on emphysema induced by elastase in mice.Methods:18 SPF male C57 mice were randomly divided into 6 groups:blank group,normal saline group,aspirin group 1(Asp1),Asp2,Asp3 and Asp4.The emphysema induced by using the experimental results in chapter 1:solution with an elastase concentration of 3.0u per 20g body weight per time,for 4 times.During the period,except the blank group,all groups were treated intragastric administration,the normal saline group was given normal saline gavage,and the aspirin groups were given aspirin suspension gavage,once per day each.After 4 weeks,bilateral whole lungs were taken for routine HE staining and the histological measurements were performed,including mean linear intercept(MLI)and mean alveolar numbers(MAN).Results:All mice survived.Pulmonary emphysema was induced successfully in each group of mice.The histological measurements during different groups had no statistical difference(P>0.05).Conclusion:Results of this experiment showed different concentrations of aspirin caused no any obvious effect on the formation of emphysema induced by elastase in mice.Differences were not significant.Aspirin may need more time to affect the formation of emphysema.Maybe the mechanism of aspirin in COPD has no cross with that of emphysema induced by elastase in this study.Further investigation like chronic research may needed.