Oestradiol feedback stimulation of androgen biosynthesis by human theca cells.
This study analysed the effect of oestradiol on basal and LH-stimulated production of androstenedione and progesterone by human theca cells in monolayer culture. Incubations were carried out for either 2 days (seven experiments) or 4 days (four experiments), in the presence or absence of luteinizing hormone (LH), oestradiol (10(-9)-10(-6) M) or inhibin. Medium collected at 48 and 96 h was stored until radioimmunoassay for steroid content. Theca pooled from small follicles (<10 mm) was used in all but two experiments; in these, ovaries were obtained from ovulatory women in the mid-follicular phase of their cycle and theca from small and large follicles was pooled. Oestradiol inhibited progesterone production in a dose-dependent manner in all experiments, irrespective of follicle size, ovulatory status and ovarian morphology, with maximum effect at 10(-6) M. At this dose, oestradiol had no effect on androstenedione production by theca from four anovulatory women with polycystic ovaries but produced a significant augmentation of both basal and LH-stimulated androstenedione production in theca from five of the seven ovulatory women, with maximal response in theca from the two pre-ovulatory subjects. During the 48-96 h period of incubation, oestradiol augmented androstenedione production in all four experiments and had a greater stimulatory effect than the physiological dose of inhibin (10 ng/ml). This is the first report of oestradiol regulating human theca cell steroidogenesis in a dose-dependent manner.
Gilling-Smith
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Department of Obstetrics and Gynaecology, Imperial College School of Medicine at St Mary's, London, UK.
Willis
D S
DS
Franks
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S
D000328:Adult; D000735:Androstenedione / Q000096:biosynthesis*; D000858:Anovulation / Q000188:drug therapy; D002478:Cells, Cultured; D016895:Culture Media, Serum-Free; D004958:Estradiol / Q000627:therapeutic use*; D005246:Feedback; D005260:Female; D006801:Humans; D007265:Inhibins / Q000627:therapeutic use; D007986:Luteinizing Hormone / Q000494:pharmacology*; D010060:Ovulation / Q000187:drug effects; D011374:Progesterone / Q000096:biosynthesis*; D013268:Stimulation, Chemical; D013799:Theca Cells / Q000187:drug effects*
D016895:Culture Media, Serum-Free; D000735:Androstenedione; D011374:Progesterone; D004958:Estradiol; D007265:Inhibins; D007986:Luteinizing Hormone