Dynamic changes of IL-2/IL-10, sFas and expression of Fas in intestinal mucosa in rats with acute necrotizing pancreatitis.

Aim: To investigate dynamic changes of serum IL-2, IL-10, IL-2/IL-10 and sFas in rats with acute necrotizing pancreatitis. To explore the expression of Fas in intestinal mucosa of rats with acute necrotizing pancreatitis (ANP).

Methods: A total of 64 Sprague-Dawley (SD) rats were randomly divided into two groups: normal control group (C group), ANP group (P group). An ANP model was induced by injection of 50 g/L sodium taurocholate under the pancreatic membrane. Normal control group received isovolumetric injection of 9 g/L physiological saline solution using the same method. The blood samples of the rats in each group were obtained via superior mesenteric vein to measure levels of IL-2, IL-10, sFas and calculate the value of IL-2/IL-10. The levels of IL-2, IL-10 and sFas were determined by ELISA. The severity of intestinal mucosal injury was evaluated by pathologic score. The expression of Fas in intestinal mucosal tissue was determined by immunohistochemistry staining.

Results: Levels of serum IL-2 were significantly higher in P group than those of C group (2.79 +/- 0.51 vs 3.53 +/- 0.62, 2.93 +/- 0.89 vs 4.35 +/- 1.11, 4.81 +/- 1.23 vs 6.94 +/- 1.55 and 3.41 +/- 0.72 vs 4.80 +/- 1.10, respectively, P < 0.01, for all) and its reached peak at 6 h. Levels of serum IL-10 were significantly higher in P group than those of C group at 6 h and 12 h (54.61 +/- 15.81 vs 47.34 +/- 14.62, 141.15 +/- 40.21 vs 156.12 +/- 43.10, 89.18 +/- 32.52 vs 494.98 +/- 11.23 and 77.15 +/- 22.60 vs 93.28 +/- 25.81, respectively, P < 0.01, for all). The values of IL-2/IL-10 were higher significantly in P group than those of C group at 0.5 h and 2 h (0.05 +/- 0.01 vs 0.07 +/- 0.02 and 0.02 +/- 0.01 vs 0.03 +/- 0.01, respectively, P < 0.01, for all), and it were significantly lower than those of C group at 6 h (0.05 +/- 0.02 vs 0.01 +/- 0.01, P < 0.01) and returned to the control level at 12 h (0.04 +/- 0.01 vs 0.05 +/- 0.02, P > 0.05). In sFas assay, there was no significant difference between P group and C group (3.16 +/- 0.75 vs 3.31 +/- 0.80, 4.05 +/- 1.08 vs 4.32 +/- 1.11, 5.93 +/- 1.52 vs 5.41 +/- 1.47 and 4.62 +/- 1.23 vs 4.44 +/- 1.16, respectively, P > 0.05, for all). Comparison of P group and C group, the pathological changes were aggravated significantly in P group. Immunohistochemistry staining show the expression of Fas was absent in normal intestinal tissues, however, it gradually increased after induction of pancreatitis in intestinal tissue, then reached their peaks at 12 h.

Conclusion: Fas were involved in the pathogenesis of pancreatitis associated intestinal injury. The mechanisms of Fas may be associated to Fas mediated T helper cell apoptosis.