动物造模,结肠炎 z-bio 2023-09-12 851

　　1. Animal modeling materials: Adult rats, male and female, weighing 200-250g; Drugs: 2,4-dinitrochlorobenzene, acetone, acetic acid, ethanol; Instrument: 3mm diameter nylon catheter.

　　2. Model making method: After one week of adaptive animal feeding, the neck and back of the animals were depilated, and 20g/L dinitrochlorophenylacetone solution (DNCB 2.0g, acetone 100ml) was dripped once a day, 0.3ml each time, for 14 consecutive days. On the 15th day, a 3mm diameter nylon catheter was inserted into the colon at a distance of 8cm through the anus, and 0.25ml of 0.04mmol/L (1g/L) DNCB ethanol solution was injected. On the 16th day, 2ml of 80ml/L acetic acid solution was injected into the same site, and accurate timing was recorded for 15 seconds. Then, physiological saline was used for rinsing.

　　3. Modeling principle: DNCB is a toxic chemical that binds to tissue proteins and has a semi antigen effect, capable of inducing T cell dependent cell-mediated immune responses. Repeated exposure can cause allergic reactions in experimental animals.

　　4. Changes after modeling 1-2 weeks after modeling, symptoms of mucus, pus, bloody stools, or loose stools may appear, lasting for more than 16 weeks, with acute attacks and chronic development. After the action of acetic acid, acute phase pathological manifestations can be observed, and after 2-5 weeks, it turns into chronic phase manifestations. The ulcer heals, but chronic inflammation persists.