Association between the expression of mast cell chymase and intraperitoneal adhesion formation in mice

Adhesion formation is a major source of postoperative morbidity and mortality. Mast cells and their major protease, chymase, have been shown to participate in the healing process as well as in tissue remodeling. We aimed to identify the role of mast cells in intraperitoneal adhesion formation and to assess whether there is an association between the expression of mast cell chymase and adhesion formation.

Both mast cell-deficient W/W(V) mice and congenic +/+ mice received a standardized lesion produced by cecal scraping and the application of 95% ethanol. Adhesions were assessed blindly 1 week later using a standardized scale. In addition, histamine content, mast cell numbers, and chymase activity in cecum as well as at the healing sites were evaluated before and 7 days after surgical injury.

A significant reduction in adhesion formation was seen in mast cell-deficient W/W(V) mice (P < 0.05). In the normal cecum, histamine content did not significantly differ between W/W(V) and +/+ mice. Chymase activity in cecum was detected in control +/+ mice, but not in W/W(V) mice. Mast cell numbers and chymase activity levels at the healing sites of +/+ mice were significantly increased 7 days after surgery.

Our results indicate that mast cells contribute to intraperitoneal adhesion formation in mice, and suggest that chymase originating from mast cells is important in the development of adhesions.