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Markers of ovarian antral follicular development in sheep: comparison of follicles destined to ovulate from the final or penultimate follicular wave of the estrous cycle.

Abstract

Treatment of non-prolific western white-faced ewes with prostaglandin F(2α) (PGF(2α)) and medroxyprogesterone acetate (MAP) increases the ovulation rate as a result of ovulations from the penultimate wave in addition to the final wave of the cycle. The objective of the current study was to evaluate the expression of markers of vascularization/angiogenesis, a marker of intercellular communication, and cellular proliferation and apoptosis in follicles from the penultimate and final waves. On day 8 of the estrous cycle, 15 ewes were administered a single injection of PGF(2α) and an intravaginal MAP sponge, which remained in place for 6 days. Two days after sponge removal, ovaries which contained follicles from the penultimate and final waves were collected and processed for immunohistochemistry followed by image analysis, and for quantitative real-time RT-PCR. Expression of factor VIII (marker of vascularization), proliferating cell nuclear antigen, and GJA1 (Cx43; marker of gap junctional communication) was greater (P<0.05) in follicles from the final wave compared with follicles from the penultimate wave. For theca cells, mRNA expression for vascular endothelial growth factor (VEGF) was greater (P<0.05) and tended to be greater (P≤0.1 and ≥0.05) for GJA1 and endothelial nitric oxide synthase in follicles from the final wave compared with follicles from the penultimate wave. For granulosa cells, the mRNA expression for GJA1 was greater (P<0.05) and tended to be greater (P≤0.1 and ≥0.05) for VEGF in follicles from the final wave compared with follicles from the penultimate wave. In conclusion, extension of the lifespan of follicles in the penultimate wave reduces follicular viability in the ewe.

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  • Authors

    Seekallu SV, Toosi BM, Grazul-Bilska AT, Rawlings NC

    Source

    Reproduction (Cambridge, England) 140:4 2010 Oct pg 559-68

    MeSH

    Animals
    Connexin 43
    Dinoprost
    Estradiol
    Estrous Cycle
    Factor VIII
    Female
    Follicle Stimulating Hormone
    Granulosa Cells
    Immunohistochemistry
    Medroxyprogesterone Acetate
    Ovarian Follicle
    Ovulation
    Progesterone
    Proliferating Cell Nuclear Antigen
    RNA, Messenger
    Reverse Transcriptase Polymerase Chain Reaction
    Sheep
    Theca Cells
    Vascular Endothelial Growth Factor A

    Pub Type(s)

    Comparative Study
    Journal Article
    Research Support, Non-U.S. Gov't

    Language

    eng

    PubMed ID

    20634390