Lipopolysaccharide promotes early endometrial-peritoneal interactions in a mouse model of endometriosis.

Purpose : The aims of this study were to clarify the effects of lipopolysaccharide (LPS) on the early development of endometriosis and on the production of cytokines and chemokines in the murine peritoneal cavity. Methods : Endometriotic lesions were induced in C57BL/6J adult female mice by intraperitoneal injection of endometrial fragments plus blood or endometrial fragments plus blood with LPS. On day 7, endometriotic lesions were assessed by gross and microscopic evaluations. Time-dependent changes in the secretion of TNF-alpha, IL-6, and CXCL2/MIP-2 in peritoneal lavage fluid after the intraperitoneal injection of LPS (50 mu g/body) were measured by their respective enzyme-linked immunosorbent assays. Results : The areas of endometriotic lesions in the LPS group (10.8 +/- 8.6 mm(2)) were significantly larger than those in the control group (3.1 +/- 3.7 mm(2)).The levels of TNF-alpha and IL-6 peaked within 2 hours and the level of MIP-2 reached a maximum on day 1 after the injection of LPS. Conclusions : LPS promotes development of the early stages of murine endometriotic lesions.