[Effect and mechanism of formation of intrauterine adhesion at different dose of estrogen].

OBJECTIVE: To investigate the effect and mechanism of the formation of intrauterine adhesion (IUA) at different dose of estrogen. METHODS: Thirty-three New Zealand female rabbits were randomly divided into low estrogen group, normal physiological estrogen group, moderate estrogen group and high estrogen group. Animals of the low, moderate and high groups were ovariectomized (OVX) while normal group underwent sham operation. The moderate and high group animals received 0.5 mg or 1.0 mg estradiol benzoate after OVX twice a week respectively. Two weeks later, all animals received curettage under direct vision. Serum was collected regularly to determine levels of estradiol (E(2)), transforming growth factor β(1) (TGF-β(1)) and basic fibroblast growth factor (bFGF). Two weeks after curettage, we cut open cavity to collected endometrium for HE and Masson staining to score extent of endometrial fibrosis and IUA. RESULTS: The score of extent of endometrial fibrosis in high group (6.1 ± 1.5) was higher than those in low estrogen group, normal estrogen group, moderate estrogen group (2.7 ± 2.1, 1.2 ± 1.8, 2.7 ± 2.0; all P < 0.05). The score of extent of IUA in high group (4.0 ± 2.5) was higher than that in any other groups (0.3 ± 0.8, 1.0 ± 1.6, 1.7 ± 1.9; all P < 0.05). The levels of TGF-β(1) and bFGF was correlated with the level of E(2) positively (P < 0.01) and they had positive relationship with extent of endometrial fibrosis and IUA (P < 0.05). CONCLUSION: High estrogen could accelerate endometrial fibrosis and IUA by promoting expression of TGF-β(1), bFGF.