Frequently Asked Questions and Analysis of Large Mouse COPD Model Smoked Method

Common problems and analysis of large mouse COPD model fumigation method. Chronic obstructive pulmonary disease (COPD) is a disease that can prevent and treat airflow limitation. Airflow limitation is not completely reversible. Progressive development is related to the abnormal inflammatory response of the lungs to harmful gases such as cigarette smoke or harmful particles. According to the data of the Ministry of Health of China, among the top ten causes of death in China, respiratory diseases (mainly COPD) accounted for 13.89% in the city, ranking fourth; in rural areas, 22.04%, ranking third. The number of deaths due to COPD in China is 1.28 million per year, which is equivalent to 2.5 deaths per minute in COPD. However, its exact etiology and pathogenesis have not yet been fully understood. A COPD animal model similar to the pathophysiological changes and clinical features of human COPD has been established, which has become a focus of global COPD researchers.

Smoking is the most important cause of COPD. In many models, fumigation is considered to be the best method for modeling COPD, but it is also difficult and the most difficult method to implement. It is only because the fumigation model has a long implementation period, lack of standardized procedures and measurement, and so on. Based on the experience of the COPD fumigation model for many years, the author shares some experiences with you and hopes to provide some help to your experiments.

1. Animal type: Rat or mouse can be used. There is no uniform standard. There are many models of rats in China.

2, the way of fumigation: according to the funding situation, there are mouth and nose exposure system and full body exposure (that is, the most common smoke box) are available. The mouth-nose exposure system adopts a tower chamber structure, which has the characteristics of good air mobility, uniform smoke, and easy adjustment of the concentration in the warehouse, but the equipment cost is relatively expensive; the ventilation and gas quality of the smoke box are poor. It is also difficult to control and monitor the precise parameters. However, due to its simple structure, easy operation, relatively low price, and even self-made, it is the most common in domestic laboratories.

3, the volume of the smoke box and the number of animals: because the nose and nose exposure system uses sophisticated air conditioning control and unique tower structure design, each structure will have a fixed number of animals used, generally no experimental animals The number and the volume of the warehouse. However, the smoke box has poor airflow effect, and its box structure has no clear indication and requirements for animals, so it is often difficult to handle in the experimental design. Here, the author summarizes a formula for everyone's reference, that is, the relationship between the volume of the box (V) and the number of animals (N) and the size of the animal (in terms of mass): V = G (in grams) × N ÷ 0.05.

4, fumigation time: Because different strains of large mice are sensitive to cigarette smoke, the total fumigation time is different, generally takes 3 to 6 months, of which the fumigation time is not less than twice a day. At least 30 minutes each time, each time interval is not less than 4 hours. Among them, the quality requirements for air: CO concentration is about 1000ppm, O2 concentration is ≥18%, and CO2 concentration is ≤5%.

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