动物造模,药效评价,溃疡性结肠炎 z-bio 2024-07-17 339

　　1. Modeling material animals: Adult rats, male or female, weighing 250-400g; Medications: physiological saline, formaldehyde.

　　2. Modeling method: Take the colon contents of a healthy rat, streak them on an eosin methylene blue plate, culture at 37 ℃ for 24 hours, amplify typical bacterial colonies, and perform numerical identification to confirm that they are Escherichia coli. Store them in the refrigerator for future use. Before immunization, the bacterial strain was amplified and killed with formaldehyde. The bacteria were washed twice with physiological saline and the concentration was adjusted to 1.2 × 10 ^ 8 ^ -1/ml. On the first day, 0.2ml of bacterial suspension was injected into the plantar area of rats. On the 10th and 17th days, 0.4ml and 0.6ml were injected subcutaneously at multiple points on the abdomen and back, respectively. On the 24th day, 1.2ml was injected intraperitoneally.

　　3. The modeling principle uses the normal bacterial population of rats as antigens, and as the number of immunizations increases, it triggers an immune response in rats.

　　4. After modeling, with the increase of immune frequency, ulcers and diffuse inflammation gradually appeared in the colon wall of rats, while cellular immunity decreased and circulating immune complexes increased. Two weeks after immunization, soft stool and positive occult blood in stool appeared. Three weeks later, mucous stool appeared, accompanied by symptoms such as decreased appetite, weight loss, fatigue, and loose hair. After 31 days, typical ulcerative colitis symptoms were observed and gradually worsened. Histopathological examination confirmed the conditions for ulcerative colitis.

　　5. Precautions: The technical key of this model is the need for certain facilities and techniques for the preparation of Escherichia coli suspension. This method has simple experimental operation, convenient antigen source, high success rate, and produces symptoms similar to clinical practice, but the experimental period is long.