Change of proinflammatory cytokines follows certain patterns after induction of endometriosis in a mouse model

Objective To examine the change in proinflammatory cytokines in the pathologic processes of endometriosis in mice. Design A dynamic study on a murine model of endometriosis. Setting Medical school. Animal(s) Female BALB/c mice. Intervention(s) Endometriosis was induced by injecting endometrial fragments of syngenic mice into the peritoneal cavity of model mice; in control group, phosphate-buffered saline instead of fragments was injected. The peritoneal fluid and the endometriotic lesions were harvested 1 to 21 days after the induction. Main Outcome Measure(s) The endometriotic lesions were weighed, the gene and protein levels of some proinflammatory cytokines, including interleukin 1β, tumor necrosis factor α, vascular endothelial growth factor, and monocyte chemoattractant protein 1, were determined by real-time quantitative polymerase chain reaction and enzyme-linked immunosorbent assay, respectively. Result(s) The levels of these cytokines reached the first peak on the first day and no endometriotic lesions were found. The lesions began to appear on the second day, presenting red color during the initial 6 days, and then they turned dark-red, brown, or bluish. The adhesion took place on the 9th day, and all the lesions evolved into white or transparent cysts on the 15th day. Corresponding to these changes, the second and the third peaks were identified during the 3rd–6th day and the 12th-15th day, respectively. Conclusion(s) The change pattern of cytokines over time might bear some relationship with the development and progression of the endometriosis.