Customized Acetic Acid-Induced Colitis Models

Among the chemical-induced inflammatory bowel disease (IBD) models, acetic acid-induced colitis is a commonly used and easily induced model with pathogenesis, histopathologic features, and inflammatory mediator profiles that closely resemble those of human IBD. Intra-rectal administration of dilute acetic acid solution induces a non-permeable inflammation characterized by increased neutrophil infiltration into the intestinal tissue, massive mucosal and submucosal necrosis, vasodilation, edema and submucosal ulceration, all of which are hallmarks of human colitis. Acetic acid-induced colitis in animals is characterized by an imbalance between oxidants and antioxidants. It is well documented that neutrophil infiltration leads to the production of superoxide anion and triggers a cascade reaction that produces a variety of active substances.

Fig. 1. By modulating important signaling cascades, gliclazide is able to attenuate or reduce the inflammation and damage caused by acetic acid-induced colitis. Fig. 1. Gliclazide attenuates acetic acid-induced colitis via the modulation of PPARγ, NF-κB and MAPK signaling pathways. (Arafa et al., 2020)

Our Acetic Acid-Induced Colitis Models

Ace Therapeutics' team of experts has the experience to provide reliable animal models of acetic acid-induced colitis to meet your specific research needs. We can also use this model to help you understand the pathophysiology of IBD and preclinical screening of therapeutic compounds for novel treatments. From modeling to drug efficacy evaluation, we are a one-stop shop.

Acetic Acid-Induced Colitis Modeling Methods

Rats

After rats are anesthetized, a catheter is inserted 6-8 cm into the rectum, and 3%-4% acetic acid is slowly injected, maintaining contact for 30 seconds. Then it is rinsed twice with 5 mL of saline and inverted for 30 s to prevent fluid from flowing out of the colon. Animals are executed and their blood and colon are collected 24-48 hours after induction of colitis for various histopathological and biochemical studies.

We also modify the procedure for achieving colitis like condition after administering acetic acid to the animals by different approaches. These methods include confining the acetic acid to the colon; injecting air (2 mL) after the enema to allow complete diffusion of the acetic acid into the colon; and rinsing the colon lumen with saline (5 mL) 20 seconds after the enema.

Mice

To induce colitis in mice, we use a catheter to drop 1 mL of acetic acid (4 to 5%, v/v) in 0.9% saline into the colonic lumen approximately 4 cm from the anus and invert it for 30 seconds to prevent fluid from flowing out of the colon.

Model Characteristics

The model resulted in rectal ulceration and mucosal injury sometimes extending into the lamina propria of the intestinal mucosa, which began to heal within a few days in the mouse model but took several weeks in the rat model.

Preclinical Evaluation in Acetic Acid-Induced Colitis Models

Ace Therapeutics offers a variety of tests to validate the effectiveness of acetic acid-induced colitis models and use the model to determine the mechanism of IBD and evaluate effective therapeutic agents.

Closely monitor clinical symptoms such as diarrhea, rectal bleeding, and weight changes.
Macroscopic analysis. Macroscopic mucosal damage is assessed, scored, and quantified by Morris et al. scoring system. Each damaged tissue is extracted and the extent of damage is assessed by light microscopy.
Pathologic analysis. Samples are stained with HE, and neutrophil infiltration, goblet depletion, and crypt abscess of sampled tissues are assessed.
Biochemical analysis. The total antioxidant capacity of each sample is assessed using the ferric reducing ability of plasma (FRAP) method, and the H₂O₂ levels in the tissues were assessed using the ferrous ion oxidized dimethylphenol orange (FOX) method.

Relying on our expertise in the field of IBD, we can customize a high-quality acetic acid-induced colitis model for you, providing a reliable experimental platform for your research. If you have any questions about our services, please feel free to contact us.

Reference

Arafa, E. S. A., et al. (2020). Gliclazide attenuates acetic acid-induced colitis via the modulation of PPARγ, NF-κB and MAPK signaling pathways. Toxicology and applied pharmacology, 391, 114919.

! For research use only, not intended for any clinical use.