STIMULATING EFFECTS OF 4-CHLORODIPHENYL ETHER ON SURGICALLY INDUCED ENDOMETRIOSIS IN THE MOUSE

The objectives of this study were to evaluate the effects of repeated injection of 4-chlorodiphenyl ether (4-CDE) on the survival and growth of endometriotic implants, Endometriosis was surgically induced in ad ult female B6C3F1 mice (n = 25) after ovariectomy, Seven days later th e animals were randomly divided into five groups and treated with vehi cle alone (corn oil, control), or 20 mu g/kg/d estrone (positive contr ol), or 10, 75, or 150 mg/kg/d 4-CDE in vehicle for 28 d, The number a nd size of the endometriotic cysts were recorded and the cysts were th en harvested for histology at necropsy 2 d after the last treatment, T here mere significantly more cysts formed (P < 0.05) in the 150 mg/kg/ d 4-CDE group compared to the vehicle-treated control (60 vs. 8%), but not compared to the estrone-treated positive control (90 vs. 60%), He patic enzymes were evaluated to confirm exposure and to further clarif y the enzymatic route of 4-CDE biotransformation by the liver, In conc lusion, the repeated exposure to 4-CDE increased the survival rates of the endometriotic cysts in the ovariectomized mouse, which suggests t hat 4-CDE mimics estrogen effects on endometriotic tissues because the endometrial tissues are dependent on estrogenic support for survival. (C) 1997 Elsevier Science Inc.