THE CELLULAR-ACTIVITY OF DIFFERENT-SIZED FOLLICLES IN CYCLES TREATED WITH GONADOTROPIN-RELEASING-HORMONE ANALOG

The activity of granulosa cells derived from different sized follicles surrounding oocytes of apparently comparable maturity was evaluated i n hyperstimulated ovaries, Granulosa cells were obtained from women un dergoing gamete intra-Fallopian transfer procedures who had been treat ed with gonadotrophin-releasing hormone analogue and gonadotrophins. O nly follicles with oocytes of apparently comparable maturity were cons idered, Granulosa cells from large and small follicles (greater than o r equal to 18 and <15 mm diameter respectively) collected from each pa tient were cultured separately for up to 48 h in the presence or absen ce of follicle-stimulating hormone (FSH; 50 ng/ml) or insulin (at vary ing doses, 0.005-25 mg/ml), We found that aromatase activity was elici ted by FSH plus insulin, but not by FSH alone, in granulosa cells from both large and small follicles, Progesterone production was maximal i n granulosa cells from large follicles, and in these cells was insensi tive to further stimuli, in contrast with those collected from small f ollicles. Prostaglandin oestradiol was secreted in large amounts by gr anulosa cells from large follicles. Cyclic adenosine monophosphate (cA MP) concentration did not differ between cells from large and small fo llicles, Our data demonstrate that there are significant differences i n granulosa cells derived from different sized follicles with oocytes of apparently comparable maturity.