Expression and significance of neutrophil elastase in infectious brain injury of infantile rats induced by lipopolysaccharide

Abstract

Objective To establish the brain injured models induced by lipopolysaccharide (LPS) in the infantile rats, and then, investigate the expression changes ofneutrophil elastase (NE) in the models to explore its mechanism. Methods Eighty 1-month-old SD rats were randomly divided into LPS inducement group (injected LPS via external carotid, n=40) and control group (injected normal saline via external carotid, n=40). Each group was equally subdivided into 2 subgroups: 24 and 48 h after the injection groups, respectively. Rats were drawn blood at different time points to detect the content of NE,and then, they were decapitated to detect the content of NE and Evans blue (EB) by the methods of formamide and enzyme linked immunosorbent assay, respectively. Results The content of EB and NE in the brain tissue and the content of NE in the serum in LPS inducement group were significantly higher than those in the control group at each time point (P＜0.05). Positive correlation was noted between the content of NE and EB in the brain tissue 24 and 48 h after the LPS inducement (r =0.903, P＜0.00 1; r =0.908, P＜0.001). Conclusion NE involves in the process of infectious brain injury of infantile rats,which is positively correlated to the damage degree of blood-brain-barrier. Key words: Neutrophil elastase; Lipopolysaccharide; Brain injury