动物造模,药效评价,溃疡性结肠炎 z-bio 2024-07-01 295

　　1. Animal modeling materials: Adult rats, regardless of gender, weighing 250-400g; Medications: physiological saline, formaldehyde.

　　2. Method of modeling: Take the colon contents of a healthy rat, streak them on an eosin blue plate, culture at 37 ℃ for 24 hours, amplify typical colonies, and perform numerical identification. Once confirmed as Escherichia coli, store them in the refrigerator for future use. Before immunization, the bacterial strains were collected and amplified, and then formaldehyde was used to kill the bacteria. The bacteria were washed twice with physiological saline and the concentration was adjusted to 1.2 × 10 to the 8th power/ml. On the first day, 0.2ml of bacterial suspension was injected into the soles of rats. On the 10th and 17th days, 0.4ml and 0.6ml were injected subcutaneously at multiple points on the abdomen and back, and 1.2ml was injected intraperitoneally on the 24th day.

　　3. The principle of modeling is based on the normal bacterial community of rats as antigens, and as the number of immunizations increases, it causes immune reactions in rats.

　　4. Changes after modeling: As the number of immunizations increases, ulcers and diffuse inflammation gradually appear in the colon wall of rats, accompanied by a decrease in cellular immunity and an increase in circulating immune complexes. After 2 weeks of immunization, there were soft stools and positive occult blood in feces. After 3 weeks, there were mucous stools accompanied by decreased appetite, weight loss, fatigue, and hair looseness. After 31 days, typical ulcerative colitis symptoms were observed, which gradually worsened. Histopathological examination met the conditions for ulcerative colitis.

　　5. Notes: 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.