Fachbereich Veterinärmedizin



    Increased expression of cyclooxygenase-1 (COX-1) and -2 mRNA after ovulation in the bovine oviduct (2004)

    Odau, S
    Gabler, C
    Einspanier, R.
    48th Annual Meeting of the German Society of Endocrinology (DGE)
    Dresden, 03. – 06.03.2004
    Experimental and clinical endocrinology & diabetes — S. V4
    ISSN: 0947-7349
    Institut für Veterinär-Biochemie

    Oertzenweg 19 b
    14163 Berlin
    Tel.+49 30 838 62225 Fax.+49 30 838-62584

    Abstract / Zusammenfassung

    Optimal conditions for fertilization and development of the early embryo is provided by the mammalian oviduct. Prostaglandins (PGs) are present in the bovine oviduct playing an important role in muscle contraction or as survival factors. COX-1 and -2 are key enzymes in the synthesis of prostaglandins by converting arachidonic acid into PGH2 as a precursor of various PGs. The aim of the present study was to investigate the mRNA expression of COX-1 and COX-2 in different regions (ampulla and isthmus) of the bovine oviduct during the estrous cycle. Bovine oviducts were collected at the slaughterhouse throughout the estrous cycle and classified into the following four phases: pre-ovulatory, post-ovulatory, early or late luteal phase. The obtained oviducts were divided in ipsilateral (to ovulation/dominant follicle) or contralateral oviducts. Oviductal epithelial cells were harvested by flushing separately the ampulla and the isthmus. Total RNA was extracted and semi-quantitative RT-PCR was performed followed by quantitative real-time RT-PCR. Expression of COX-1 and -2 mRNA was detected in all regions of the oviduct during the whole estrous cycle. Quantitative real-time RT-PCR revealed a significant higher expression of COX-2 in the ampulla compared with the isthmus during all stages of the estrous cycle. The highest expression of COX-2 was observed in the ipsilateral ampulla directly after ovulation. In contrast, COX-1 showed a twofold higher mRNA expression after ovulation compared with the other estrous cycle phases. No difference between ipsilateral and contralateral oviducts nor between the ampulla and the isthmus was noted. These results showed that both COX were differently expressed in a cycle stage-dependant manner. Especially the expression pattern of COX-2 suggests that an estrous cycle-dependant and region-specific synthesis of PGs is required for a successful reproduction. Therefore, we hypothesize that a local PG synthesis may directly influence survival and transport of the ovulated egg as well as of the early embryo