Histological changes of pancreatic tissue architecture after repetitive caerulein and combined caerulein-lipopolysaccharide (LPS) injections. (A) Hematoxylin and eosin staining indicates destruction of pancreatic acinar cells and development of tubular complexes, a sign of chronic pancreatitis. (B) Masson-Goldner trichrome stain denotes fibrosis; connective tissue is stained green. Caerulein and LPS increase pancreatic fibrosis compared to caerulein alone. Phosphate-buffered saline (PBS)-treated mice did not develop chronic pancreatitis and were used as negative controls.