Effects of different concentrations of dexamethasone on pulmonary histology in rats with chronic asthma

摘要

Objective:To observe the intervention effects of different concentrations of dexamethasone on the general situation and pulmonary histology of chronic asthma rats,and to explore the suitable intragastric dose of dexamethasone in the rat model of chronic asthma.Methods:75 healthy male Sprague-Dawley(SD)rats were randomly divided into normal group,M group,dexamethasone low dose,middle dose and high dose group by random number table.The rat model of chronic asthma was established by sensitization and challenge of ovalbumin(OVA).From the 20th day of the experiment,dexamethasone groups were given intragastric administration of 0.0625mg/(kg·d),0.125mg/(kg·d)and 0.5mg/(kg·d),respectively.The general situation of rats was observed and recorded.The histological changes of rat lungs were observed by HE staining and Masson staining.Results:The degree of inflammatory infiltration of bronchus and surrounding tissue in the M group was significantly higher than that in the normal group(P0.05).A large number of rats in the high dose group died after 5 times of intervention.Three rats died in the DEXM group at the 5th week of intervention,and there was no death in the other group.Conclusion:Both middle and low doses of dexamethasone can be used as the positive control dose in the experiment of chronic asthmatic rats,but the late side effects of low dose of dexamethasone are less,so the low dose of dexamethasone may be a safer and more suitable dose for the experiment of chronic asthmatic rats.