Change and significance of IL-8, IL-4, and IL-10 in the pathogenesis of terminal Ileitis in SD rat.

The objective of the study is to explore change and significance of IL-8, IL-4 and IL-10 in the pathogenesis of terminal Ileitis in SD rat. 60 male SD rats were divided into model group, suture group, and control group equally. The rats subjected to ileum-cecum side-to-side anastomosis in terminal ileum in model group, suture in terminal ileum in suture group, and the control group accepted no special treatment. The terminal ileum tissue which was 1-3 cm from anastomotic stoma was collected at 2 and 8 weeks after surgery in each group. The pathological slice was observed under microscope, and PCR was applied to detect the expression of IL-4, IL-8, and IL-10 at different times. Pathological result showed that neutrophils significantly increased in model group and suture group at 2nd week, showing acute inflammatory reaction; model group showed chronic inflammation at 8th week. The change of IL-8, IL-4, and IL-10 expression level at 2 weeks after surgery: The IL-8 expression level of SD rat terminal ileum tissue in model group was significantly higher than in control and suture groups (P < 0.01), and it was higher in suture group compared to control group (P < 0.01); the expression level of IL-4 in control group was higher than model and suture groups (P < 0.05); there was no statistical significance between model group and suture group (P = 0.363); the expression level of IL-10 in control group was higher than in model and suture groups (P < 0.01), and it was higher in suture group compared to model group (P < 0.01). The change of IL-8, IL-4, IL-10 expression level at 8 weeks after surgery: The expression level of IL-8 significantly decreased in model group, and there was no significantly difference between three groups (P > 0.05); the expression level of IL-4 was higher in model group and suture group compared to 2nd week; there was no significance between three groups (P < 0.05); the expression of IL-10 was higher in model group compared to 2nd week (P < 0.01), it was lower than control group and suture group (P < 0.01); there was no significant difference between suture group and control group (P > 0.05). The chronic terminal ileum model could be successfully established by ileum-cecum side-to-side anastomosis in terminal ileum in SD rats; IL-8 can induce the inflammatory reaction in terminal ileitis and chemokines aggregation and mediate inflammatory reaction by mediating other inflammatory factors; as a proinflammatory cytokine, IL-8 can inhibit IL-10; IL-10 and IL-4 can inhibit the inflammatory reaction of terminal ileum.