Induction of endometriosis in mice: a new model sensitive to estrogen

Endometriosis consists of the growth of endometrial tissue outside the uterus. A rat model of endometriosis is available to evaluate the potential for environmental chemicals to promote the disease but may be relatively insensitive for the evaluation of the hazard of certain compounds. Our objective, which was to develop a mouse model for endometriosis, was based on (a) the promotion of endometriosis in primates by 2, 3, 7, 8-tetrachlorodibenzo-p-dioxin (TCDD), (b) the apparent relationship between endometriosis and immunodeficiency, and (c) evidence that humoral immunity is suppressed in mice but not rats following TCDD exposure. In the mouse model, slices of uterus were sutured to intestinal mesenteric vessels. By 3 weeks after surgery, these sites were cyst-like structures. The growth of the sites was hormone dependent. In intact mice, sites measured 3.60 +/- 0.22 mm; vehicle and estrone (0.5 microgram/day) treatments produced site diameters of 0.95 +/- 0.128 and 5.28 +/- 0.355 mm, respectively. This new mouse model provides a sensitive and useful technique for future studies of the potential for specific xenobiotics to promote the development of endometriosis.