Effect of lilopristone on serum levels of luteinizing hormone and estradiol in experimental endometriosis rats

AIM: To observe the effect of lilopristone (Lil) on the serum levels of luteinizing hormone (LH) and estradiol (E 2) in the rat of experimental endometriosis. METHODS: Twenty rats of the experimentally induced endometriosis were randomly divided into 4 groups. They were daily given intragastrically with Lil 20 mg·kg -1, 80 mg·kg -1, mifepristone (Mif) 50 mg·kg -1 and peanut oil 4 mL·kg -1 for 21 d, respectively. Blood specimens were collected in the morning of d 19, 20, 21 of giving the drugs and 24 h after withdrawal. Serum LH activity was determined by the rat interstitial cell testosterone (RICT) assay, and serum E 2 level was measured by specific radioimmunoassay. RESULTS: In control rats, cyclical changes in serum LH and E 2 levels were shown, the proestrus LH and E 2 surge appeared. In the rats treated with Lil 20, 80 mg·kg -1 and Mif 50 mg·kg -1, cyclical changes in serum LH and E 2 levels appearing in the control rats disappeared, and the proestrus LH and E 2 surge were abolished. CONCLUSION: As Mif, Lil could inhibit the secretion of LH and E 2, and abolish the proestrus LH and E 2 surge.