Mouse Model for Acute Pancreatitis (AP)

Group A: pancreatitis model with mild symptoms:

Intraperitoneally, one day a week, Cerulein was injected 50 µg/kg (1.25µg/ mouse) 7 times, with an interval of 1 hour. A total of 6 weeks of injection.

Group B: severe pancreatitis model:

Weekly: 33% ethanol 150ul, 3g/kg, intraperitoneal injection twice from 1d to 3d. Two abdominal intervals of 12 hours. On the 4th day, Cerulein was intraperitoneally injected for 7 times, 50 µg/kg (1.25µg/ mouse) at an interval of 1 hour.

150ul 33% ethanol was intraperitoneally injected twice at 3g/kg (75mg per animal) from 5 d to 7 d. Two abdominal intervals of 12 hours.

The above modeling lasted for 6 weeks.

Group C: Normal group.

At the 6th week of modeling, the animals in each group were sacrificed and fresh pancreatic tissues were collected. Fixed to 4% paraformaldehyde for more than 24h. Remove the tissue from the fixative solution and smooth the tissue of the target part with a scalpel in the ventilation cabinet. Put the cut tissue and the corresponding label in the dehydration box, and then dehydrate, fix, encapsulate and slice.

HE and Masson staining were performed to determine the degree of pancreatic fibrosis.

HE staining results: Group A was mild pancreatitis, group B was severe pancreatitis, and group C was normal. Compared with group C, group B had adipose vacuolation degeneration of islet cells, loose edema of some acinar cells, and eagle-eyed giant cell lesion of some acinar cells. Compared with group C, group A had no obvious islet lesions and vascular hyperplasia. Not as severe as group B.

Masson staining results: Group A was mild pancreatitis group, group B was severe pancreatitis group and group C was normal group. Compared with group C, pancreatic vascular perivascular and islet fibrosis, lipoid vacuole degeneration of islet cells, and amyloidosis of acinar cells also occurred in group B. Compared with group C, only peripheral vascular fibrosis was found in group A, and pancreatic islet and acinar cells had no obvious lesions.

The acute pancreatitis model can be evaluated by the combined detection of serum para-amylase, urinary amylase, blood lipase, glutamic-pyruvate aminotransferase, serum creatinine and lactate dehydrogenase.

SPSS software is used for statistical analysis, measurement data to mean ± standard deviation (x ±ｓ), using t test and single factor analysis of variance for group comparison , P<0.05 indicates there was a significant difference, P<0.01 indicates there are very significant differences.