Establishment and applicability evaluation of animal model of inhalation of atmospheric fine particles

  Objective: To establish an animal model of body damage caused by chronic inhalation of atmospheric fine particulate matter (PM2.5) aerosol.

  Method: Prepare PM2.5 aerosol continuous inhalation device. Investigate different concentrations (100±10 μg/m3, 150±10 μg/m3, 200±10 μg/m3), different time (1 week, 2 weeks, 4 weeks, 8 weeks, 12 weeks), different methods (non- Exposure to the effects of intratracheal perfusion and aerosol inhalation) and different animals (Wistar rats, BN rats and guinea pigs) on the establishment of the model. Observe the general state of the animal and calculate the weight growth rate and mortality; test lung function including respiratory rate, forced expiratory volume, occupancy vital capacity ratio (FEV1/FVC) and arterial oxygen partial pressure (PO2); count bronchoalveolar lavage fluid (BALF) ) Cell classification; light microscopic examination of trachea and lung tissue pathology. Taking pneumonia in pathology of trachea and lung tissues as the criterion for establishing a successful model, determine the influencing factors of establishing the model.

  Results: After continuous inhalation of PM2.5 aerosols of different concentrations for 8 weeks, Wistar rats were poisoned, weight gain was slow, the total number of white blood cells and mononuclear cell counts in bronchoalveolar lavage fluid (BALF) increased, the ratio of macrophages increased, and the lungs Among the functional indicators, respiratory frequency increased, arterial blood PO2 and FEV1/FVC decreased, pathology showed inflammation and pulmonary fibrosis changes in trachea and lung tissues. Inflammation changes were positively correlated with the exposure concentration, but high concentrations had high mortality. Inhalation of the same concentration for different periods of time (1 week, 2 weeks, 4 weeks, 8 weeks and 12 weeks), the pathological changes of the trachea and lung tissues of the Wistar rats exposed to the poisoning animals were significant from 8 weeks but no difference from 12 weeks. Different methods (non-exposure intratracheal perfusion method and aerosol inhalation method) Wistar rats were continuously inhaled for 8 weeks. The two methods had the same effect but the inhalation method had low animal mortality. Wistar rats, BN rats and guinea pigs were inhaled continuously for 8 weeks. The effects of the three animals were equivalent but the mortality rate of Wistar rats was low.

  Conclusion: Using Wistar rats to inhale PM2.5 aerosol with a concentration of 150±10 μg/m3 for 8 consecutive weeks can establish a suitable animal model of PM2.5-induced body damage, and study and prepare a pathogenic similar to PM2.5 damage to the body Environment, taking the lead in establishing a model that is not only suitable for a large scale in the country, but also has the characteristics of Fujian Province, which causes damage to the body of PM2.5, which will promote the development of PM2.5 prevention and treatment measures.