Nose-only cigarette smoke exposure plus airway lipopolysaccharide inhalation induced chronic obstructive pulmonary disease and associated pulmonary hypertension in mice

OBJECTIVE: To establish a mouse model of chronic obstructive pulmonary disease (COPD) and associated pulmonary hypertension (COPD-PH) induced by nose-only cigarette smoking exposure plus airway lipopolysaccharide (LPS) inhalation.

METHODS: There were 24 male C57B6 mice divided into a control group and a model group at random. The model group was given LPS by intranasal inhalation on day 1 and day 14 and exposed to the cigarette smoke in a nose-only exposure system, while the control group was given physiological saline and exposed to normal air. The model establishment was evaluated according the following parameters: the lung function and the right heart pressure, the total and differential cell numbers in bronchial alveolar lavage fluid (BALF), and the pathological changes of lung tissues.

RESULTS: The functional residual capacity data of the model group and the control group were (0.402 ± 0.057) and (0.243 ± 0.064) ml respectively (P<0.05). The inspiratory resistance data of the model group and the control group were (1.056 ± 0.121) and (0.789 ± 0.063) cmH(2)O · ml(-1) · s(-1) (1 cmH(2)O=0.098 kPa) respectively (P<0.05). The static lung compliance data of the model group and the control group were (0.084 ± 0 .007) and (0.056 ± 0.004) cmH(2)O/ml respectively (P<0.05). The right ventricular mean pressure of the model group and the control group were (11.3 ± 1.3) and (7.9 ± 1.1) mmHg (1 mmHg=0.133 kPa) respectively (P<0.05), while the right ventricular hypertrophy index of the model group and the control group were (0.267 ± 0.019) and (0.195 ± 0.023) respectively (P<0.05). Moreover, the histological staining showed that goblet cell hyperplasia, lung inflammation and thickening of smooth muscle layers of bronchial and pulmonary small vessels occurred in the model group, which indicated ongoing airway and blood vessel remodeling.

CONCLUSIONS: A COPD-PH mouse model was established by nose-only cigarette smoking exposure plus airway LPS inhalation in a short period of time, and this method was more similar to the smoking behavior of human.