Macrophages Linked to Postoperative Ileus
In animal studies, inhibiting macrophages reduces inflammatory response after surgery
FRIDAY, Feb. 23 (HealthDay News) -- Depleting intestinal muscularis macrophages before surgery reduces the inflammatory responses that lead to postoperative ileus, according to the results of an animal study published in the February issue of Gut.
Jorg C. Kalff, M.D., of the University of Bonn in Germany, and colleagues depleted and inactivated resident muscularis macrophages in rodents either chemically using chlodronate liposomes or genetically. After intestinal surgery, the investigators measured inflammation in the intestinal muscularis as well as in vitro jejunal circular muscle function and in vivo gastrointestinal transit.
Removing intestinal macrophages markedly reduced the expression of inflammatory mediators, including a marker of macrophage activation (MIP-1α), inflammatory mediators (IL1β, IL6), an adhesion molecule (ICAM-1), and a chemokine (MCP-1) after surgery. Depletion also reduced leukocyte infiltration into the muscularis. Jejunal muscle function and gastrointestinal transit were normal in the macrophage-depleted animals after surgery, the report indicates.
"Resident intestinal muscularis macrophages are initially involved in inflammatory responses resulting in postoperative ileus," Kalff and colleagues conclude. "Depletion and inactivation of the muscularis macrophage network prevents postoperative ileus."