动物造模 z-bo 2022-10-20 494

　　Chronic bronchitis (chronic bronchitis) refers to chronic non-specific inflammation of the trachea, bronchial mucosa and surrounding tissues caused by infectious or non-infectious factors. The pathological features of chronic bronchitis are bronchial gland hyperplasia and increased mucus secretion. Clinically, symptoms such as cough, sputum, and wheezing occur repeatedly, each of which lasts for 3 months or longer and lasts for 2 years or longer. Obliterative emphysema and even cor pulmonale may also aggravate the condition. Chronic bronchitis is mainly seen in the elderly. In the early stages of the disease, the general symptoms of the disease are mild. The onset season is mainly in winter, and the symptoms are reduced when the weather is warm in spring. The late stage usually indicates that the inflammatory response is worse than before, and symptoms are present regardless of the season or season. At present, chronic bronchitis is one of the main diseases affecting human health and quality of life, and it is very important to study its treatment and prognosis. Chronic bronchitis occurs due to smoking, infection, climatic factors (such as colds), physical and chemical factors (irritating smoke, dust, SO2, etc.), allergies, decreased local airway defense and immune function, and decreased autonomic nerve function. It is related to internal and external factors (such as disability). This is closely related. [Modeling mechanism] Various destructive factors that can cause chronic bronchitis due to long-term stimulation are applied to animals, causing chronic inflammation of the trachea, bronchial mucosa and surrounding tissues. The main methods of inducing chronic bronchitis are: chemicals (sulfur dioxide, chlorine, ammonia, lipopolysaccharide, enzymes, adrenergic agonists, cholinergic agonists, secretagogues, etc.), bacterial infection methods (Klebsiella pneumoniae) ), Streptococcus pneumoniae, etc.), passive smoking methods (raw tobacco, straw smoke, mixed smoke, etc.) and complex methods (bacteria and smoke, bacteria and colds, etc.). These methods can be used alone or in combination.

　　[Modeling method]

　　1. Chemical method (1) Inhale air containing SO2 (concentration 2%) for 10 seconds every day. Mice developed bronchitis lesions after 14 to 18 days, and severe bronchial lesions after 27 days. The typical observation time is 97 days. Daily inhalation contains

　　(2) Cl2 (concentration of 0.001 to 0.004 mg/L) air for 25 to 30 minutes. After 35 days, the mice may develop chronic bronchitis lesions. The total observation time is 50 days.

　　(3) Repeat the stimulation with ammonia-containing air every 15 to 20 minutes for 2-3 minutes. Stimulate 8 times a day. Symptoms of chronic bronchitis appeared after 32 days. The total observation time is 100 days. .. Intratracheal injection (4) lipopolysaccharide: intraperitoneally anesthetize the rat with 1% sodium pentobarbital, fix it on the operating table in the supine position, pull out the tongue, expose the glottis, and quickly insert the cannula into the trachea. Inject 200μg/200μl lipopolysaccharide into the trachea. After feeding for 4 weeks, a rat model of chronic bronchitis was prepared.

　　2, bacterial infection method

　　(1) Use chicken embryo fluid to cultivate influenza virus, and select chicken embryo fluid that has been cultured for 48 hours. The unit is 1:320. Haemophilus influenzae is cultured for 18 to 24 hours, and the concentration of the bacterial solution is 7×100,000,000 ml. The mice were injected intranasally with an infectious agent (0.03 ml/mouse) under ether anesthesia. Mild necrosis of the tracheal epithelium appeared in 3-6 days, and typical symptoms of chronic bronchitis appeared after 35 days. ..

　　(2) Haemophilus influenzae 900 million ml/ml, Streptococcus A 100 million ml/ml, catarrhal inflammatory bacteria 900 million g/ml, Streptococcus pneumoniae under mixed anesthesia at 4:3:2:1 600 million ml/ml When rats were given 0.1 ml bacterial solution once a week for 6 weeks, they tended to develop chronic bronchitis, but to a very mild degree. Every three days will

　　(3) The guinea pigs were placed in an environment of 7-8°C for 1 hour, and placed twice a week later for 45 days. At the same time, 0.2 ml of bacteria mixed bacteria solution (8 species) was added to the nose for 150 days. The formation of subacute and chronic bronchitis lesions.

　　3. Passive smoking law

　　(1) The method of chronic bronchitis by rat smoke: Put the rat in a 27 cubic meter smoke chamber, mix 150-200 mg/cubic meter of smoke (200 grams of wood chips, 15-20 grams of tobacco leaves, 6 peppers) G? Mix 7 g) with 1 g of sulfur, burn within 20-30 minutes, inhale particles larger than 0.5-1μm, 6 times a week, and form chronic bronchitis lesions within 44 days.

　　(2) Burn a cigarette in a 21-liter container for 10 minutes, ventilate for 5 minutes, then burn another cigarette for 10 minutes, and then smoke again. Guinea pigs are placed in a smoked environment once a day, 6 times a week, and placed in an environment of 7-8°C for 1 hour, and replaced every other day, twice a week, 45 days each time, 28-35 days each time. There was a chronic bronchitis lesion, which persisted and gradually worsened after 6 weeks.

　　[Model Features] The animal model of chronic bronchitis caused by SO 2 inhalation has the following features. ① The mice had an irritating cough, did not gain weight, and even died. Pathological changes of the bronchus: the initial stage is acute inflammation, lymphocytes and plasma cells infiltrate after the 12th day, and after the 27th day, severe chronic bronchitis appears in the connective tissue around the bronchial hyperplasia. (2) When rat tracheal mucus is blocked, tracheal epithelium will undergo necrosis/erosion, goblet cell proliferation, tracheal wall smooth muscle proliferation, alveolar space expansion and partial fusion, forming blisters. This method also replicates a stable and reliable animal model. No changes were observed in the number and function of muscarinic receptors (M receptors) in the respiratory tract and lung tissues.

　　In bronchitis caused by bacterial infection, hair loss, cough, wilting, anorexia, mild necrosis of tracheal epithelium appeared in 3-6 days after infection, and the number of goblet cells initially decreased after 10 days, and after 35 days Gradually increase, show the typical symptoms of chronic bronchitis, and return to normal after 50 days. Twenty-one days after the tracheal instillation of lipopolysaccharide, rats experienced fatigue, discoloration of hair, reduced food intake, shedding of tracheal and bronchial epithelium, goblet cell hyperplasia, mucous gland hyperplasia, and chronic inflammation of the tracheal and bronchial walls. The affected cells are infiltrated, the tube wall is thickened, the tube cavity is filled with a large number of inflammatory cells, mainly mucus and neutrophils, and the tracheal smooth muscle is hypertrophy and hypertrophy. In chronic bronchitis in rats caused by smoke, with the increase of smoke stimulation time, the damage of rat tracheal inflammation gradually increased, and by the 7th week, typical chronic bronchitis changes were formed. Inflammatory cells in the trachea are characterized by early macrophages, then lymphocytes, and neutrophils appear at high levels only during the initial and short-term exposure to smoke.

　　[Model Evaluation and Application] There are many ways to establish chronic bronchitis models, but the most commonly used SO2 stimulation method is mainly to study the etiology and etiology of chronic bronchitis, which is used to screen preventive and therapeutic drugs. Although this method has a high success rate, it needs to detect the daily SO2 concentration, requires complicated equipment and operations, and is time-consuming and labor-intensive. The main pathological changes in this model are inflammatory cell infiltration and goblet cell proliferation in the trachea and submucosa. As SO2 is a harmful gas, inhalation usually causes severe respiratory mucosal burns, cell atrophy, necrosis, epithelial cell proliferation, punctate and scaly squamous metaplasia, resulting in acute respiratory death of animals. The mixed bacterial infection method of rats and guinea pigs is mainly used to study the etiology of chronic bronchitis, whether the virus is the cause of chronic bronchitis and the role of respiratory bacteria in the development of chronic bronchitis. I will. If the dose of lipopolysaccharide is too high, acute lung injury only occurs after endotoxemia, and the inflammatory process cannot be observed in stages. In addition, a rat model of chronic bronchitis with immune damage was constructed by combining the tail vein injection of 5 mg BCG vaccine and the intratracheal injection of 200 μg lipopolysaccharide for 3 weeks. Compared with lipopolysaccharide alone, the pathological changes in rat trachea are more typical. However, the morphological changes of tracheal gland hyperplasia cannot be reproduced well because the tracheal glands of rats have not yet developed and are limited to the upper part. The smoking method of rats with chronic bronchitis can reflect a series of early inflammatory processes, which are simple and easy to perform, and are unlikely to suffer from other complex diseases. This method is mainly used to study the pathological changes and various stages of chronic bronchitis. Inflammatory cell infiltration and corresponding changes in inflammation markers.