Ovine follicular fluid inhibits thymidine incorporation by 3T3 fibroblasts in vitro

Carson, Ronald S.; Robertson, D.M.; Findlay, J. K.

doi:10.1530/jrf.0.0820447

Cited by 9 publications

(5 citation statements)

References 25 publications

(27 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A similar protein of molecular mass 10 kDa is present in ovine follicular fluid which inhibits [3H]thymidine incorporation in fibroblasts (Carson et al, 1988). The stimulatory effects were found in the molecular mass range of > 30 kDa.…”

Section: Discussionmentioning

confidence: 92%

Control of peptides regulating mitosis of granulosa cells in immature rat ovary by oestrogen and gonadotrophin

Chakravorty¹,

Mahesh²,

Mills³

1993

Reproduction

View full text Add to dashboard Cite

Previous studies in this laboratory have demonstrated the presence of a peptide that inhibits granulosa cell proliferation in medium sized follicles. This peptide was produced after 72-96 h of exposure to diethylstilboestrol (DES). This study analyses oestrogen and gonadotrophin modulation of this and another stimulatory peptide found in large follicles. Intact, immature, female rats were assigned to the following study groups: (i) one to four injections of DES (2 mg per rat) given at intervals of 24 h, animals killed 24 h after the last injection; (ii) DES at 0 and 24 h, animals killed 24 or 48 h after the last injection; and (iii) DES plus pentobarbital (37 mg kg-1 body weight) at 30 h, animals killed 48 h after the last injection. Small, medium and large follicles (diameters of < 200, 200-400 and > 400 microns, respectively) were isolated from ovaries, granulosa cells were harvested and follicular fluid supernatant (FFS) was collected. FFS proteins were tested for their effects on incorporation of [3H]thymidine into granulosa cell DNA. Results showed that unfractionated FFS protein (150 micrograms) from medium follicles in groups (i) (three and four injections only), (ii) and (iii) inhibited [3H]thymidine incorporation. Pentobarbital blockage of gonadotrophin secretion had no effect on the inhibitory peptide activity and two injections of diethylstilboestrol were enough to stimulate synthesis of the inhibitory peptide, provided sufficient time was allowed; FFS protein (150 micrograms) from large follicles was stimulatory, but only when it was collected 24 h after the second injection, and the effect was abolished with pentobarbital treatment. Fractionation of pooled FFS into proteins with three molecular mass ranges (< 10 kDa, 10-30 kDa and > 30 kDa) showed that the inhibitory activity was in the < 10 kDa fraction while the > 30 kDa fraction stimulated thymidine incorporation. The number of medium and large follicles increased 24 h after the second DES injection, but the number of granulosa cells in the large follicles was significantly reduced after pentobarbital blockage of gonadotrophins. Taken together, these findings show that (i) the inhibitory peptide is induced in effective amounts in the medium follicles 48 h after the second DES injection and induction is not modulated by gonadotrophins; and (ii) stimulatory activity seen in the large follicles is transient and under gonadotrophic control, since blockage of follicle-stimulating hormone (FSH) secretion led to loss of stimulatory activity and a resulting reduction in number of granulosa cells in large follicles.(ABSTRACT TRUNCATED AT 400 WORDS)

show abstract

Section: Discussionmentioning

confidence: 92%

Control of peptides regulating mitosis of granulosa cells in immature rat ovary by oestrogen and gonadotrophin

Chakravorty¹,

Mahesh²,

Mills³

1993

Reproduction

View full text Add to dashboard Cite

show abstract

“…Cahill et al demonstrated that ovine follicular fluid inhibited the development of follicles >2 mm in diameter in the ovary and reduced the mitotic index of the granulosa cells of follicles <2 mm (Cahill et al, 1985). Later, substances with molecular weights of 18 000 and <10 000 kDa were identified in ovine follicular fluid that inhibited the mitotic activity of murine embryonic lung fibroblasts (Carson et al, 1988). Campbell et al reported a substance in the ovine pre-ovulatory follicle that is atresia-inducing and results in a loss of steroidogenic activity following injection into the cycling sheep (Campbell et al, 1991).…”

Section: 'Inductive Signalling' and Follicular Dominancementioning

confidence: 99%

The role of intra-ovarian interactions in the regulation of follicle dominance

Baker¹,

Spears²

1999

Human Reproduction Update

View full text Add to dashboard Cite

The processes that precisely control the selection of ovulatory follicles from a growing cohort are poorly understood. This reduction in follicle number occurs through several phases of selection, consequently we limit the use of the term 'selection' to the first major reduction of growing follicles, at the pre-to early antral stage. The final process of selection, achieving the appropriate ovulatory number, is referred to as 'dominance'. We discuss possible mechanisms that could bring about these reductions and highlight intra-ovarian involvement, particularly via follicle-follicle interactions. Analogies are drawn between local ovarian events and processes commonly reported in the determination of cell fate in developmental biology. Two facets of intra-follicular interactions are proposed: initially that follicle-follicle interactions mediate early selection processes at the preantral stage, and later that during antral development dominant follicles directly affect the fate of the subordinate cohort members.

show abstract

“…Hypotheses regarding direct follicular interactions have been suggested now for many years, but have proven difficult to investigate in vivo [1]. Despite such difficulties, several extracts of follicular fluid have been proposed to play a role in folliclefollicle interactions [9][10][11][12][13][14], but their in vivo roles have yet to be established.…”

Section: Introductionmentioning

confidence: 99%

Mouse Ovarian Follicles Secrete Factors Affecting the Growth and Development of Like-Sized Ovarian Follicles In Vitro1

Spears

Baker

Sršeň

et al. 2002

Biology of Reproduction

View full text Add to dashboard Cite

A series of experiments have been carried out to determine whether follicles secrete factors able to affect the growth and development of other, like-sized follicles. Late preantral mouse ovarian follicles were either cocultured or cultured in media conditioned by previously cultured follicles. In particular, the experiments examined whether follicles do secrete such factors, whether the level of FSH in the culture media can affect that process, and what the nature of such secretory factor(s) might be. First, pairs of follicles were cocultured across a polycarbonate membrane containing pores. This showed that communication between the follicles resulted in the stimulation of growth and that the stimulation was due, at least in part, to the production of secretory factor(s). In subsequent experiments, follicles were cultured in media that had been preconditioned by previously cultured follicles. The concentration of FSH in the cultures determined the effect of the conditioned media: conditioned media was stimulatory to follicle growth when levels of FSH remained high throughout the culture, but inhibitory when FSH levels were dropped midway through the cultures. Heat inactivation removed this inhibitory effect, showing that the factor was likely to be a protein; addition of follistatin to the conditioned media did not alter its effect, indicating that the factor was unlikely to be activin. We have shown through a series of culture experiments that mouse follicles secrete factor(s) that can affect the development of other like-sized follicles when cultured from the late preantral to Graafian stages. Furthermore, we have shown that the effect (or production) of such factors is dependent on the FSH environment of the follicles.

show abstract

Ovine follicular fluid inhibits thymidine incorporation by 3T3 fibroblasts in vitro

Abstract: Summary. The

Cited by 9 publications

References 25 publications

Control of peptides regulating mitosis of granulosa cells in immature rat ovary by oestrogen and gonadotrophin

Control of peptides regulating mitosis of granulosa cells in immature rat ovary by oestrogen and gonadotrophin

The role of intra-ovarian interactions in the regulation of follicle dominance

Mouse Ovarian Follicles Secrete Factors Affecting the Growth and Development of Like-Sized Ovarian Follicles In Vitro1

Contact Info

Product

Resources

About