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 pot ential for environmental chemicals to promote the disease but may be r elatively insensitive for the evaluation of the hazard of certain comp ounds. Our objective, which was to develop a mouse model for endometri osis, was based on (a) the promotion of endometriosis in primates by 2 , 3, 7, 8-tetrachlorodibenzo-p-dioxin (TCDD), (b) the apparent relatio nship between endometriosis and immunodeficiency, and (c) evidence tha t humoral immunity is suppressed in mice but not rats following TCDD e xposure. In the mouse model, slices of uterus were sutured to intestin al mesenteric vessels. By 3 weeks after surgery, these sites were cyst -like structures, The growth of the sites was hormone dependent. In in tact mice, sites measured 3.60 +/- 0.22 mm; vehicle and estrone (0.5 m u g/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.