Abstract: We combined five endpoint s into a single 52day in vivo screening assay to identify est rogenicity of enosulfan. The endpoint s evaluated as markers of esrogenicity included the ratio of uterine weight/ body weight , uterine fluid imbibition , vaginal cornification incidence , uterine st roma cell proliferation and uterine epithelial cell height . The endosulfan were administered daily p. o. for 5 days to sexually mature ovariectomized female NIH mice. Compared with the five endpoint s of the three dosage groups of edosulfan (0. 5mg/ kg/ d ,1. 5mg/ kg/d and 3. 0 mg/ kg/ d) showed no significant difference and no significant dose2response. Thus , endosulfan has no est rogenicity under the experimental condition.

Key words: Endosulfan, Est rogenicity, Multiple endpoint s