MCP-1 is highly expressed in peritoneum following midline laparotomy with peritoneal abrasion in a murine model

Background: Monocyte chemoattractant protein-1 (MCP-1), a CC chemokine, is a potent attractant of monocytes both in vitro and in vivo. However, its role in the repair of peritoneal injury is not well established. This study characterizes MCP-1 expression in surgical wounds following peritoneal abrasion in a murine model. Methods: Twenty-five C57 BL6 female mice underwent a 2-cm midline laparotomy with mechanical abrasion of the right peritoneal wall. The mice were sacrificed at various times ranging from 0 to 7 days. Hemotoxylin and eosin stained sections and tissue extracts were made using peritoneal samples from abraded and unabraded areas in each mouse. An enzyme-linked immunosorbent assay was performed on the specimens to quantitate MCP-1 expression. Values were compared using a t-test. Results: At baseline, there was minimal expression of MCP-1 (< 5 pg/mg protein). Following surgery, MCP-1 levels at abraded sites were significantly higher than those at both baseline and unabraded sites at all times up to a week following surgery. Histologic evaluation revealed peritoneal thickening and leukocytic infiltration of only abraded surfaces. Conclusion: MCP-1 is highly expressed in peritoneum following laparotomy with peritoneal abrasion. Elevations in MCP-1 levels are identified within 6 h of surgery and persist for up to I week. The histologic differences between abraded and unabraded areas may be attributable to differences in MCP-1 expression. Further studies using recombinant MCP-1 and anti-MCP-1 antibody may elucidate this relationship.