A selective cyclooxygenase-2 inhibitor suppresses the growth of endometriosis with an antiangiogenic effect in a rat model

OBJECTIVE: To analyze the antiangiogenic effects of the selective cyclooxygenase-2 (COX-2) inhibitor parecoxib on the growth of endometrial implants in a rat model of peritoneal endometriosis. DESIGN: Pharmacologic interventions in an experimental model of peritoneal endometriosis. SETTING: Research laboratory in the Federal University of Rio de Janeiro. ANIMAL(S): Twenty female Sprague-Dawley rats with experimentally induced endometriosis. INTERVENTION(S): After implantation and establishment of autologous endometrium onto the peritoneum abdominal wall, rats were randomized into groups and treated with parecoxib or the vehicle by IM injection for 30 days. MAIN OUTCOME MEASURE(S): Vascular density, the expression of vascular endothelial growth factor (VEGF) and its receptor Flk-1, the distribution of activated macrophages, the expression of COX-2, and the prostaglandin concentration in the endometriotic lesions treated with parecoxib were analyzed. RESULT(S): The treatment significantly decreased the implant size, and histologic examination indicated mostly atrophy and regression. A reduction in microvessel density and in the number of macrophages, associated with decreased expression of VEGF and Flk-1, also were observed. The treatment group showed a low concentration of prostaglandin E(2). CONCLUSION(S): These results suggest that the use of COX-2 selective inhibitors could be effective to suppress the establishment and growth of endometriosis, partially through their antiangiogenic activity.