A Mouse Model for Chronic Pancreatitis via Bile Duct TNBS Infusion

Abstract

Chronic pancreatitis (CP) is a complex disease involving pancreatic inflammation and fibrosis, glandular atrophy, abdominal pain and other symptoms. Several rodent models have been developed to study CP, of which the bile duct 2,4,6 -trinitrobenzene sulfonic acid (TNBS) infusion model replicates the features of neuropathic pain seen in CP. However, bile duct drug infusion in mice is technically challenging. This protocol demonstrates the procedure of bile duct TNBS infusion for generation of a CP mouse model. TNBS was infused into the pancreas through the ampulla of Vater in the duodenum. This protocol optimized drug volume, surgical techniques, and drug handling during the procedure. TNBS-treated mice showed features of CP as reflected by bodyweight and pancreas weight reductions, changes in pain-associated behaviors, and abnormal pancreatic morphology. With these improvements, mortality associated with TNBS injection was minimal. This procedure is not only critical in generating pancreatic disease models but is also useful in local pancreatic drug delivery.

Figure 1:. TNBS bile duct infusion for CP mice generation.

(A) Illustration of bile duct injection. (B) Bile duct after injection of 50 μL of ink. (C) Averages of body weight change in mice receiving TNBS or vehicle. (D) Abdominal response threshold in TNBS and control mice at 3 weeks after infusion. Data were analyzed using available analysis software (e.g., GraphPad 8.2.1). Data are presented as mean ± SEM. Differences between groups were analyzed using the Student's t-test, ** p < 0.01 was considered statistically significant.

Figure 2.. Characterization of CP in TNBS-treated mice.

(A) Micrographs of the pancreas from control (CTR) and TNBS mice. (B) The average pancreas weight divided by mouse bodyweight in CTR and TNBS mice. (C) Hematoxylin and eosin staining of pancreas sections of CTR and TNBS mice. Scale bar =100 μm. Data are presented as mean ± SEM. **, p < 0.01 by Student's t-test.