动物造模 z-bo 2022-02-03 402

　　[Modeling mechanism] When the allergen (usually used ovalbumin) is injected into guinea pigs, its soluble antigen components will stimulate the body to produce IgE, which leads to an allergic state. When the animal comes into contact with the antigen again, the antigen-antibody reaction is mediated by IgE, which degranulates the cells and releases active chemicals that act on the bronchus and cause airway hyperresponsiveness, such as histamine and eosinophil chemokine. asthma. Mice: BALB/c mice, select about 20g, intraperitoneally inject 0.2ml ovalbumin antigen solution (containing 100μg ovalbumin and 1mg aluminum hydroxide), and give the same dose again 8 days later. Using only one injection, BALB/c mice were placed in a closed container from the 15th day and challenged with a 60 g/L ovalbumin solution spray for 30 minutes once a day for 60 consecutive days. Rats: Choose male Sprague Dawley rats weighing 120-180g and inject 1ml antigen solution (containing 100mg ovalbumin, 5×1000000000 inactivated Bordetella pertussis vaccine and 100mg aluminum hydroxide dry powder) by intraperitoneal injection Sensitization. Then, after 7 days, repeat it once for sensitization. After 2 weeks, use an ultrasonic atomizer to spray 1% ovalbumin (3-5μm in diameter) into the self-made spray box once a day for 2 minutes each time and 30 minutes each time. Irritating to animals after inhalation.

　　Guinea pig: Choose a healthy male guinea pig weighing 300-500 g, and inject 10 ml of 10% ovalbumin saline intraperitoneally to make the guinea pig allergic; 2 weeks later, put the guinea pig in a sealed container and use 10% To induce asthma attacks in guinea pigs, spray the protein saline and inhale it for 20 minutes. Alternatively, 10 ml of 10% ovalbumin solution (100 mg ovalbumin) is injected intraperitoneally, and the animal is inhaled with 0.5% ovalbumin saline for 13 seconds after 14 to 13 days. Or, choose 200-300 g guinea pigs (male and female), add 10 ml 0.5% ovalbumin (dissolved in physiological saline) to the ultrasonic nebulizer on day 1 and day 8, and cover the guinea pig with a simple mask. Nebulized inhalation for 10 minutes. On day 16-20, place the sensitized guinea pig in a sealed container, stimulate with 1% ovalbumin aerosol, and expose the animal to ovalbumin aerosol for 10-30 minutes. Until they become asthmatic. Do it. Until the attack. [Model Features] Commonly used mouse models are BALB/c and C57BL/6, BALB/c are prone to airway hyperresponsiveness, easily sensitized by ovalbumin, and produce high titers of IgE. However, C57BL/6 tends not to have a high airway response and only produces low titer IgE. However, house dust mites (HDM) are prone to allergies and can be used to create HDM-induced allergic asthma models. The rat model shows a consistent response to the antigen, and may exhibit a delayed phase response similar to human asthma, with eosinophil infiltration and increased airway reactivity. In recent years, the use of rat models has gradually increased. The brown Norwegian rat is used abroad, while the Sprague Dawley or Wistar rat is used in China. Male rats are usually selected. The sensitization method is basically the same. The immediate phase reaction occurs 3-5 minutes after excitation, and the delayed phase reaction occurs 2-4 hours after excitation. Later, various inflammatory cell infiltrations appeared in the lungs, mainly due to an increase in granulocyte eosinophils within 24 hours. At this time, the airway responsiveness of rats increased, and increased by about 7 to 10 times, and lasted for 4 to 5 days. Repeated provocation can prolong the duration of airway hyperresponsiveness, but it cannot increase airway hyperresponsiveness or increase eosinophil infiltration. The guinea pig model is easily sensitized and may cause type I allergic reactions. After sensitization, inhalation of ovalbumin can cause acute airway allergic reactions, such as immediate and late asthma. Suitable for production. Animal models of allergic asthma are also the most commonly used models at home and abroad. Model evaluation and application] Ovalbumin is easy to obtain, inexpensive and highly immunogenic. Most commonly used to prepare asthma models. Aluminum hydroxide as an immune adjuvant can prevent desensitization and enhance sensitization. The common animals for asthma caused by ovalbumin are guinea pigs, rats and mice. Mouse models can be used to evaluate the efficacy of immune drugs in preventing and treating chronic bronchitis and asthma, but there are many limitations. Do not use mouse asthma models to study genetic polymorphisms, because almost all mice exposed to allergens will develop asthma. In addition, there are anatomical and physiological differences between the respiratory system of mice and humans. For example, the breathing rate of mice is much higher than that of humans, but the tidal volume is lower. Most asthma mouse models usually require short-term high-concentration allergies. The original exposure is obviously contrary to the long-term hypoallergenic exposure in the human natural environment, which leads to chronic airway inflammation and no epithelial changes typical of human asthma; mouse models lack Mucosal inflammation and human asthma are characterized by eosinophil infiltration of the epithelium; the immune mechanism of mice is also different from that of humans. Most mouse models have allergic alveolitis and hypersensitivity pneumonia, which mask the inflammatory damage to the respiratory tract. In addition, because the mouse is small, it is inconvenient to operate. Guinea pigs are the most widely used model of allergic reactions. Although there are great differences between this animal and humans, anti-allergic drugs for allergic bronchoconstriction (early onset, rapid onset) in sensitized guinea pigs have been studied, the most commonly used is bronchodilator. This is an animal model . Guinea pigs have many advantages as an asthma model: the animals are cheap and easy to handle. Allergen-induced bronchoconstriction has the same contraction characteristics as human bronchial asthma, including bronchoconstriction response after exposure to antigen and airway hyperresponsiveness to mediators, as well as eosinophil infiltration characteristics in allergic bronchitis. .. However, inbred guinea pigs are rare and useless for studying genetic effects. In the guinea pig asthma model, corticosteroids have little effect on bronchospasm. In addition, it should be noted that when guinea pigs are selected to create an asthma model, population-dependent exaggerated reactions may occur. Some guinea pigs die of anaphylactic shock, which wastes experimental resources. Guinea pigs are sensitive to sensitization. After receiving the sensitizer, it is more reactive than other animals. May cause type I allergic reactions. Nebulization can cause immediate and delayed asthma reactions. Therefore, guinea pigs have been one of the most widely used experimental animals for allergic asthma in Japan and abroad. Compared with guinea pigs, rats have the characteristics of pure strain, fast reproduction, low price, abundant sources and large collection of specimens, and their biological characteristics are more like humans. Therefore, studying the principle of action of glucocorticoids and studying non-glucocorticoid anti-asthma immunosuppressants are the first choice for rat asthma models. Most asthma papers using rat models published in international medical journals are based on BN rats. The main advantage of the BN rat asthma model is that it can make the body produce specific IgE antibodies against inhaled allergens, which are likely to induce asthma symptoms, obvious airway inflammation and airway hyperresponsiveness. However, the price of this mouse is higher.