Pancreatic and pulmonary mast cells activation during experimental acute pancreatitis

Figure 1 Presence of mast cells in pancreas (A-C) and lung (D-F), in control (A and D). Three hours after induction of pancreatitis (B and E) and under cromolyn treatment (C and F). Degranulating mast cells were observed in the pancreas after pancreatitis induction (B). Cromolyn treatment prevented mast cell degranulation (C). In contrast, no evident degranulation was observed in lung after induction of pancreatitis. Toluidine blue, × 40.

Figure 2 Effect of mast cell inhibitor, cromolyn. Three hours after pancreatitis induction, increased levels of lipase and histamine were detected in plasma. Cromolyn treatment had no effect on lipase, which is related to acinar cell damage, but prevented the increase in histamine. In tissue, leukocyte infiltration was evaluated by measuring myeloperoxidase (MPO) activity. Pancreatitis resulted in increased MPO activity in both pancreas and lung. Cromolyn treatment partially prevented these increases. ^aP < 0.05 vs C; ^cP < 0.05 vs AP. C: Control; AP: Acute pancreatitis.

Figure 3 Both peritoneal and alveolar macrophages were activated after induction of pancreatitis, but the expression of tumor necrosis factor α mRNA in peritoneal macrophages was one order of magnitude higher than that observed in alveolar macrophages. Tumor necrosis factor (TNF)α release was induced in peritoneal cells, while in alveolar cells the observed increase was not statistically significant. Cromolyn treatment completely prevented the activation of alveolar macrophages. In contrast, peritoneal macrophages remained activated under cromolyn treatment. ^aP < 0.05 vs C; ^cP < 0.05 vs AP. C: Control; AP: Acute pancreatitis.

Figure 4 The effect of plasma on cultured mast cell line RBL-2H3 and alveolar macrophages. Mast cells were not activated by plasma from animals with pancreatitis. In contrast, the expression of tumor necrosis factor (TNF)α in alveolar macrophages was induced by plasma from animals with pancreatitis. This induction was not observed when animals were treated with cromolyn. ^aP < 0.05 vs C; ^cP < 0.05 vs AP. C: Control; AP: Acute pancreatitis.