| Abstract: | In order to investigate the mechanism of progestin and antiprogestin in the regula tion of ovarian steroidogenesis, a dual-chamber culture system was prepared with the amnion membrane of human placenta. Isolated porcine granulosa and thecal cells from 4～6 mm-diameter follicles were grown on both sides of the amnion, respectively, and co-cultured with or without LNG and RU486. After 48 h incubation, the mRNAs of FSH receptor (FSH-R) and LH receptor (LH-R) of both cells were observed by in situ hybridization. The results showed that granulosa cells expressed both FSH-R mR NA and LH-R mRNA, while thecal cells expressed LH-R mRNA only. Under the stimulation of FSH, both LNG and RU486 increased FSH-R mRNA expression of granulosa cells. Under the stimulation of LH, LNG enhanced LH-R mRNA expres sion of thecal cells; while RU486 decreased its expression. When granulosa and thecal cells were exposed to FSH and LH both, the actions of LNG and RU486 in thecal cells showed the same result as that stimulated by LH alone. In granulosa cells LNG de creased LH-R mRNA expression, while RU486 increased its expression. These data suggest that: (1) granulosa cells expressed FSH-R mRNA significantly;(2) both the progestin and antiprogestin directly acted on the mRNA expression of gonadotropin re ceptors of ovarian cells, but effects were different; (3) the response of granulosa or thecal cells to the action of LNG and RU 486 was not the same. The mechanism needs to be further investigated. |
