Bovine ovarian follicular growth and development correlate with lysophosphatidic acid expression

IGFs are known to be key regulators of ovarian follicular growth in eutherian mammals, but little is known regarding their role in marsupials. To better understand the potential role of IGFs in the regulation of follicular growth in marsupials, expression of mRNAs encoding IGF1, IGF2, IGF1R, IGF-binding protein 2 (IGFBP2), IGFBP4 and IGFBP5 was localized by in situ hybridization in developing ovarian follicles of the brushtail possum. In addition, the effects of IGF1 and IGF2 on granulosa cell function were tested in vitro. Both granulosa and theca cells synthesize IGF mRNAs, with the theca expressing IGF1 mRNA and granulosa cell expressing IGF2 mRNA. Oocytes and granulosa cells express IGF1R. Granulosa and theca cells expressed IGFBP mRNAs, although the pattern of expression differed between the BPs. IGFBP5 mRNA was differentially expressed as the follicles developed with granulosa cells of antral follicles no longer expressing IGFBP5 mRNA, suggesting an increased IGF bioavailability in the antral follicle. The IGFBP protease, PAPPA mRNA, was also expressed in granulosa cells of growing follicles. Both IGF1 and IGF2 stimulated thymidine incorporation but had no effect on progesterone production. Thus, IGF may be an important regulator of ovarian follicular development in marsupials as has been shown in eutherian mammals.

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Gonadotrophins and Ovarian-Follicular Growth

Clinics in Obstetrics and Gynaecology ◽

10.1016/s0306-3356(21)00432-5 ◽

1978 ◽

Vol 5 (2) ◽

pp. 363-373

Author(s):

JOANNE S. RICHARDS ◽

RIAZ FAROOKHI

Keyword(s):

Follicular Growth ◽

Ovarian Follicular Growth

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Ovarian Follicular Growth, Ovulation and Atresia

Advances in Experimental Medicine and Biology - Tissue Renin-Angiotensin Systems ◽

10.1007/978-1-4899-0952-7_7 ◽

1995 ◽

pp. 103-119 ◽

Cited By ~ 19

Author(s):

Kelle H. Moley ◽

James R. Schreiber

Keyword(s):

Follicular Growth ◽

Ovarian Follicular Growth

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Role of ascorbic acid in promoting follicle integrity and survival in intact mouse ovarian follicles in vitro

Reproduction ◽

10.1530/rep.0.1210089 ◽

2001 ◽

pp. 89-96 ◽

Cited By ~ 61

Author(s):

AA Murray ◽

MD Molinek ◽

SJ Baker ◽

FN Kojima ◽

MF Smith ◽

...

Keyword(s):

Ascorbic Acid ◽

Basement Membrane ◽

Growth And Development ◽

Culture Media ◽

Membrane Integrity ◽

Tissue Inhibitor Of Metalloproteinase ◽

Follicular Growth ◽

Intact Mouse

Ascorbic acid has three known functions: it is necessary for collagen synthesis, promotes steroidogenesis and acts as an antioxidant. Within the ovary, most studies have concentrated on the role of ascorbic acid in luteal formation and regression and little is known about the function of this vitamin in follicular growth and development. Follicular growth and development were investigated in this study using an individual follicle culture system that allows the growth of follicles from the late preantral stage to Graafian morphology. Follicles were isolated from prepubertal mice and cultured for 6 days. Control media contained serum and human recombinant FSH. Further groups of follicles were cultured in the same media but with the addition of ascorbic acid at concentrations of either 28 or 280 micromol l(-1). Addition of ascorbic acid at the higher concentration significantly increased the percentage of follicles that maintained basement membrane integrity throughout culture (P < 0.001). Ascorbic acid had no effect on the growth of the follicles or on oestradiol production. Metalloproteinase 2 activity tended to increase at the higher concentration of ascorbic acid and there was a significant concomitant increase in the activity of tissue inhibitor of metalloproteinase 1 (P < 0.01). Follicles cultured without the addition of serum but with FSH and selenium in the culture media underwent apoptosis. Addition of ascorbic acid to follicles cultured under serum-free conditions significantly reduced apoptosis (P < 0.05). From these data it is concluded that ascorbic acid is necessary for remodelling the basement membrane during follicular growth and that the ability of follicles to uptake ascorbic acid confers an advantage in terms of granulosa cell survival.

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