EFFECTS OF EXOGENEOUS ESTROGEN/PROGESTIN ON THE EXPRESSIONS OF MMP_1/TIMP_1 IN ENDOMETRIOSIS OF NUDE MOUSE

Objective To observe the effect of exogenous estrogen and progestin on expression of MMP1 and TIMP1 in the endometriosis (EMs) of nude mouse. Methods An animal model of endometriosis was established through implanting the human endometrium of later secretory phase into the abdom-pelvic cavity of nude mice. The experimental animals were randomly divided into four groups: group Ⅰ treated with daily intramuscular injection of estrogen, group Ⅱ with progestin, group Ⅲ with the combination of estrogen and progestin, and group Ⅳ with normal saline. Fifteen days after injection, tissues of EMs were made into sections and further processed by immunohistochemistry to detect the expression of MMP1 and TIMP1. Results When compared with group Ⅳ, expressions of MMP1 in groups Ⅰ, Ⅱ and Ⅲ significantly increased, while expression of TIMP1 significantly decreased (F=11.134,16.758;q=3.52-4.60;P0.01). Furthermore, the expression of MMP1 in group Ⅱ was significantly stronger than that of the group Ⅰ, and the expression of TIMP1 significantly weaker (q=3.52,4.57;P0.05). No significant differences in the expressions of MMP1 and TIMP1 could be observed when comparison was made between the group Ⅱ and Group Ⅲ (P0.05). Conclusion Both strogen and the progestin can enhance the production of MMP1 and suppress the production of TIMP1, which may related to the mechanism of endometriosis.