Association between the pulmonary density and serum HSP27 in the rat model of COPD

Abstract

Objective To investigate the correlation between the pulmonary density and serum HSP27 in the rat model of COPD. Methods Forty Wistar rats were divided into 5 groups randomly (G1-G5). Each group consisted of two subgroups: COPD model group and normal control group.The rat model of COPD was made by smoking and lipopolysaccharide injected into the trachea.To evaluate the change of pathology in rats lung tissue by HE, and detect the levels of HSP27 in serum by ELISA.Each group of rat was performed by 128 slice spiral CT scanning, and the average lung density was measured.Analysis of variance (LSD-t test) was used to compare the lung density and the levels of serum HSP27 in the COPD model group, and the relationship between the lung density and HSP27 in the serum was analyzed by Pearson correlation. Results The inflammatory changes of airway in COPD model group were increased with time.The mean lung density of model group slightly decreased early.It was increased in third and four weeks while significant decreased in sixth weeks, and presented a trend of rising on the whole.The lung density of COPD model group was significantly different between groups, and the difference was statistical significance (F=23.516, P<0.01). The change of lung density was not obvious in normal control group.Compared with control group, the levels of serum HSP27 was increased in COPD model groups.The levels of HSP27 had a slightly rising tend, there were statistical significance between fourth groups and fifth groups (P<0.05). The levels of HSP27 was negatively correlated with the lung density in the COPD model group (r=-0.421, P<0.05), which was increased with the decrease of lung density. Conclusions The change of serum HSP27 reflects the severity of pulmonary emphysema, and can be used as a marker to assess the severity of COPD and lung injury. Key words: Chronic obstructive pulmonary disease; Rat model; Pulmonary density; Heat shock protein 27