Temporal expression of IL-1β and IL-10 in rat skin, muscle, small bowel, and colon wounds: a correlative study.

Background: Cytokines play a major role in coordinated wound healing events. We hypothesized that rapid intestinal healing is due to an early upregulation of the pro-inflammatory cytokine interleukin-1β (IL-1β), followed by increases in the expression of the anti-inflammatory cytokine IL-10.

Methods: We characterized the time course of IL-1β and IL-10 release at four wounds (skin, muscle, small bowel, and colonic anastomosis) after surgery on 38 juvenile male Sprague-Dawley rats. The tissue samples of each site were harvested at 0 (control), 1, 3, 5, 7, and 14 days postoperatively (n=6-8 per group) and analyzed by enzyme-linked immunosorbent assay kits for IL-1β and IL-10.

Results: IL-1β expression peaked at days 5 and 7 in small bowel and colonic wounds when compared to skin or muscle. Similarly, IL-10 showed high expression in these time points in small bowel and colonic wounds. However, IL-10 showed the same expression in all time points in muscle and skin tissues except at day 1.

Conclusions: The high expression in IL-1β and IL-10 levels in small bowel and colon might explain the accelerated healing process in these wounds in comparison to skin and muscle tissues. Additional studies are required to determine whether IL-1β and IL-10 expression is the major factor defining site-specific differences in healing rates in different tissues. Understanding cytokine action in the wound healing process could lead to novel and effective therapeutic strategies.