Effect Of Mifepristone On Experimental Endometriosis In Rats

Objective: To investigate the effects of mifepristone on endometrial tissue and explore the probable mechanism by means of the endometriosis (EMS) rat model.Methods: (1) The EMS model rats established by surgical operation were randomly divided into control group and mifepristone group (including low dose and high dose subgroups) and treated with mifepristone for 4 weeks. (2) the volume of transplant before and past treatment were measured, in order to explore the inhibitory effect of mifepristone. (3) The volume density of endometrial gland and the barrier thickness of endometrial epithelium were investigated by the stereological method. (4) the expression of COX-2 Casepase-3 and Survivin in ectopic and eutopic endometrium of each group were observed and analyzed by immunohistochemistry(S-P method). (5) Ultrastructural change in ectopic and eutopic endometrium of each group were observed by electron microscopy.Results: (1) The rat model of surgically induced endometriosis was established successfully.(2)Compared with control group, the volume of transplant in the high dose group and low one were obviously reduced(P<0.01).(3)Stereologically, the volume density of endometrial gland and the barrier thickness of endometrial epithelium in ectopic endometrium of the control group were significantly increased than those of the high dose group and low one (P<0.01).(4) In both high dose and low dose groups, the expression intensity of COX-2 and Survivin in the ectopic endometrium was lower than that of the control group, but the expression intensity of Casepase-3 was higher than that of the control group. (5) Ultrastructurally, in low dose and high dose groups, the endometrial epithelium was narrow, the microvilli on the free surface of secretory cells were short and small in number. Some microvilli broke off from the surface. Lipid droplets were prominent. There were variation of the shape and size in the nuclei. The nuclear membrane of epithelial cells showed irregularity. Apoptotic cell occurred in certain ectopic glandular epithelial cells, which displayed a decreased cell size, karyopyknosis,cytoplasmic and nuclear chromatin condensation.