title: Steroid productions by co-cultures of granulosa cells with inner and outer theca cells in preovulatory follicles of gonadotropin stimulated calves.
abstract: Granulosa, interna and externa theca cells were isolated from large follicles of equine-chorionic-gonadotropin (eCG)-primed calves and co-cultured during 3 days in the absence or in the presence of dehydroepiandrosterone (DHEA). Co-cultures were performed by adding defined numbers of theca and/or granulosa cells which represented 0, 10, 20, 50 or 100% of total cells per well. Secretion of oestradiol-17beta (E2), androstenedione (A4) and progesterone (P4) depended on the type of theca cells (P < 0.001), on the percentage of seeded granulosa cells (P < 0.001) and on the day of culture (P < 0.001). DHEA increased (P < 0.001) E2 and A4, but not P4 (P > 0.05) productions. Interactions existed between these factors (P < 0.01). On day 1, A4 production was nil in granulosa cells alone. E2 production was negligible in theca cells alone but it increased when granulosa cells were added. E2 and A4 varied in an opposite manner according to the percentage of granulosa cells and with the type of theca cells. On day 3, without DHEA, E2 and A4 were low. On day 3 with DHEA, E2 production was maintained in granulosa cells alone but not with any combination of theca cells. In these conditions, A4 production was maintained in the presence of theca cells but not in granulosa cells alone. Granulosa cells alone secreted more P4 than theca cells. P4 increased as a function of the percentage of granulosa in co-cultures with externa but not interna theca cells with which it remained low. In conclusion, theca cells in culture have two effects in relation to the granulosa cells, which differ according to the steroid concerned and to the cell combination. Both types of theca cells have an inhibitory effect on E2 secretion whereas only interna theca cells are able to alter P4 production.
authors.affiliation: Laboratoire de Physiologie de la Reproduction des Mammifères Domestiques, Institut National de la Recherche Agronomique, Nouzilly, France. mbosc@tours.inra.fr
authors.forename: M J
authors.initials: MJ
authors.lastname: Bosc
authors.forename: A
authors.initials: A
authors.lastname: Nicolle
mesh_terms: D000818:Animals; D002417:Cattle; D002450:Cell Communication; D002478:Cells, Cultured; D018920:Coculture Techniques; D005260:Female; D006062:Gonadotropins / Q000494:pharmacology*; D006107:Granulosa Cells / Q000166:cytology / Q000378:metabolism*; D013256:Steroids / Q000378:metabolism*; D013799:Theca Cells / Q000166:cytology / Q000378:metabolism*
chemical_list: D006062:Gonadotropins; D013256:Steroids