| Objective To establish a simple, efficient and accurate approach for setting up acute lung inflammation in left lung in mice through intratracheally instillation.Methods18 male C57BL/6J mice were randomly divided into three groups: NS group were intratracheally instilled with normal saline( 1 μl/g weight) into the left lung with a catheter; EB group with 0.05% Evans blue( 1 μl/g weight) by the same way; and LPS group with lipopolysaccharide( 3.5 mg/Kg weight). After anesthesia and fixed,each group of mice anterior portion was disinfected and exposed about 5 mm tube,instilled sterile saline drip / 0.05% Evans blue- saline/lipopolysaccharide-physiological saline to left lung with catheter, then slowly push note about 30 times liquid volume of air.(1) Physiological status monitoring;(2) mice pulmonary functions(Pehn) were measured at 6 hours after administration of the above reagents,each mice adapt to 5 minutes in closed box, and tested 7 ~ 10 min after numerical value stably;(3)distribution of Evans blue was observed by pathological analysis after mice were sacrificed at 24 hours after instillation.Results The general physiological status was not affected during or after 6 hours of the operation in the mice. 100% of the flexible tube was intubated in the exact site of the left main trachea and Evens blue was distributed evenly in the left lung of all the EB group mice. No differences of the pulmonary function and histopathological changes were found between the NS and EB groups, however, significantly decreased pulmonary function and sever acute lung injury under microscope were observed in LPS group.Conclusion This method of intratracheal instillation is characterized with high efficiency,accuracy, safety and good repeatability, which could be widely used in mice endotracheal instillation.Objective To explore a stable and standard acid-induced acute lung injury( ALI) mice model to support the research on the mechanism and treatment of ALI, and the mechanism of acid-induced acute lung injury(ALI) in mice.Methods The ALI model was reproduced by intra-tracheally instillation of hydrochloric acid( 1μl/g weight) into the left lung with a catheter in mice. 120 male C57BL/6J mice were randomly divided into two groups: control group( NS) and hydrochloric acid group( HCl), and each group has 5 time pionts as 30 min, 2h, 6h, 12 h and 24 h.Pulmonary function were observed( except for 30min) at each time point before the mice were sacrificed for harvesting of bronchoalveolar lavage fluid( BALF) and lung tissue. Then we detected the lung tissue wet/dry weight( W/D) ratio, the number of leukocytes in BALF and observed the lung tissue pathology morphology change at each time point. Meanwhile, immunohistochemistry were used to analyze the inflammatory cells infiltration in lung, and the protein expression of interleukin-6( IL-6), IL-1β, tumor necrosis factor-a( TNF-a) and nuclear transcription factor(NF-κB) were measured by Western blot.Results Severe lung function disorder was found at 12 h HCl group(P<0.01 vs NS), and the lung W/D of the group was also significantly higher than control group(P<0.01)and HCl group other points(P<0.05); the BALF protein concentration and total WBC in6 h HCl group are up to top level(P<0.05 vs other HCl groups,P<0.01 vs NS); the protein expression of IL-6, IL-1β, TNF-a and NF-κB were increased in lung tissue along with HCl stimulation, but decreased after 12 h; Neutrophil infiltration occurred since 30 min, and macrophages and T-lymphocytes appeared later in the lung of HCl groups.Conclusion This experiment duplicated inhalation pulmonary injury model by,hydrochloric acid-inhalation in mice, and we found that neutrophils infiltration occurred in early time while macrophages appeared later. A large number of inflammatory cytokines are involved in the whole process of disease. In addition, inhalation unilateral pulmonary injury mice model duplicated by intratracheal instillation in this study,more in line with the clinical features of aspiration pneumonia, and this model is more suitable for aspiration pneumonia research. |
