Recombinant luteinizing hormone as a survival and differentiation factor increases oocyte maturation in recombinant follicle stimulating hormone-supplemented mouse preantral follicle culture

Abstract

The effects of recombinant luteinizing hormone (rLH) and recombinant follicle stimulating hormone (rFSH) both separately and together were analysed on the in-vitro maturation of a well-defined class of mouse early preantral follicles. Metaphase-II (MII) oocytes were only obtained when rLH or rFSH or a combination of both hormones was added to a standard rich culture medium at constant doses throughout the culture period. Without gonadotrophins only 8% of the follicles reached day 12 of culture. Follicle survival was optimal (between 90 and 100%) when rFSH was used; significantly fewer follicles were kept intact when rLH was added as the only supplement (54%; P < 0.001). Theca cells played a fundamental role in follicle survival when rLH was the only supplement. Presence of rLH significantly influenced the formation of antral-like cavities: on day 12, 59% of follicles cultured with rLH + rFSH had a large cavity, as compared with only 21% in cultures with rFSH only (P < 0.0001). The rHCG stimulated germinal vesicle breakdown rate from the different gonadotrophin-supplemented cultures on day 12 was not significantly different (FSH: 89%; LH: 70%; FSH/LH: 83%). However, addition of rLH to rFSH did significantly improve (P < 0.05) the completion of the first meiotic division up to the MII stage (FSH: 46%; LH: 39%; FSH/LH: 76%). Interfollicle differences in steroid production were very large and depended on the presence of theca cells and on the kind of gonadotrophin supplemented. Without theca cells, oestrogen concentrations in rFSH-supplemented cultures were 100 times lower than their theca-containing counterparts during the entire culture period. From culture day 9 onwards most conditioned media had increased basal progesterone concentrations. This study points up the in-vitro role of LH on the differentiation of follicle-like structures and the oocyte's meiotic maturation and suggests an important role for theca cells in providing modulators of in-vitro gonadotrophin action.

Effects of luteinizing hormone and follicle stimulating hormone on the developmental competence of porcine preantral follicle oocytes grown in vitro

“…The number of cells forming the cumulus mass in LH and FSH combination cultures was lower than that with FSH alone. This result is consistent with previous work from Cortvrindt et al [19], suggesting more pronounced differentiation of the granulosa cells in the presence of LH. However, the exact mechanisms by which gonadotropins influence embryonic development are unknown.…”

“…In contrast, the action of LH in preantral follicle development has received less attention. Cortvrindt et al [19,20] have suggested that LH is a survival and differentiation factor that increases oocyte maturation in FSH-supplemented cultures of mouse preantral follicles, and LH has a stage-limited effect on mouse preantral follicle development in vitro. However, little information exists on the action of LH and FSH in the developmental competence of porcine preantral follicle oocytes in vitro.…”

Effects of dibutyryl cyclic adenosine monophosphate and human chorionic gonadotropin on the formation of antral follicle-like structures by bovine cumulus—oocyte complexes

“…FSH supplementation in a 3-D culture system of bovine oocytes stimulates the proliferation of granulosa cells that maintain their morphological qualities, consequently allowing AFLS formation and the maintenance of gap junctional communication between oocyte and cumulus cells (Harada et al, 1997). The addition of a low concentration of LH during in vitro follicular culture enhances antral cavity formation and improves the meiotic competence of oocytes (Cortvrindt et al, 1998). In contrast, LH supplementation of FSH-containing medium has been shown to have no positive effect on the growth of mouse preantral follicles (Murray et al, 2008).…”

“…The gonadotropic hormones follicle-stimulating hormone (FSH) and luteinising hormone (LH) have complementary effects: the combination of FSH and LH promotes the formation of the antral cavity in early pre-antral follicles and the acquisition of oocyte meiotic competence (Cortvrindt et al, 1998). LH promotes the production of androgens, which are aromatised in the granulosa layer under the influence of FSH (Evans et al, 1981).…”

“…LH promotes the production of androgens, which are aromatised in the granulosa layer under the influence of FSH (Evans et al, 1981). Moreover, FSH stimulates follicle survival and granulosa cell proliferation in culture of pre-antral follicles (Cortvrindt et al, 1998;Spears et al, 1998) and small oocytes from early antral follicles (Harada et al, 1997). FSH is thought to affect granulosa cells by activating adenylyl cyclase activity and promoting cAMP accumulation (Kolena and Channing, 1972).…”