Repeated use of mifepristone and levonorgestrel and their effect on the ovarian function in mice

To investigate the effects of repeated mifepristone and levonorgestrel use on estrous cycle and expression of ovarian follicle-stimulating hormone receptor (FSHR) and luteinizing hormone receptor (LHR) in mice.

Ovarian FSHR and LHR mRNA expression was measured using real-time quantitative reverse transcription-polymerase chain reaction, while the protein levels were measured using immunohistochemistry.

Repeated use of mifepristone and levonorgestrel significantly lengthened the estrous cycle and decreased FSHR and LHR mRNA and protein expression in the ovaries of mice at 4, 24, and 48 days after discontinuing drug use. Repeated use of mifepristone and levonorgestrel had significant main effects on estrous cycle length and the mRNA expression and protein level of ovarian FSHR and LHR. Repeated mifepristone and levonorgestrel use and withdrawal time had a significant interaction with mouse estrous cycle (F = 16.65, P < 0.05), ovarian LHR and FSHR mRNA expression (F = 563.072, P < 0.05), and protein level (F = 6.536, P < 0.05).

Repeated use of mifepristone and levonorgestrel can lead to sustained damage to ovarian function through inhibition of ovarian FSHR and LHR expression in mice.