Immunolocalization of Progesterone Receptors in the Canine Oviduct around Ovulation

Authors

  • MZ Tahir,

    1. INRA, UMR1198 Biologie du Développement et Reproduction, Jouy-en-Josas, France
    2. ENVA, UMR1198, Maisons-Alfort, France
    Search for more papers by this author
  • K Reynaud,

    1. INRA, UMR1198 Biologie du Développement et Reproduction, Jouy-en-Josas, France
    2. ENVA, UMR1198, Maisons-Alfort, France
    Search for more papers by this author
  • G Mawa,

    1. INRA, UMR1198 Biologie du Développement et Reproduction, Jouy-en-Josas, France
    2. ENVA, UMR1198, Maisons-Alfort, France
    Search for more papers by this author
  • S Thoumire,

    1. INRA, UMR1198 Biologie du Développement et Reproduction, Jouy-en-Josas, France
    2. ENVA, UMR1198, Maisons-Alfort, France
    Search for more papers by this author
  • S Chastant-Maillard,

    1. INRA, UMR1198 Biologie du Développement et Reproduction, Jouy-en-Josas, France
    2. ENVA, UMR1198, Maisons-Alfort, France
    Current affiliation:
    1. INP-ENVT, Reproduction, Toulouse Cedex, France
    Search for more papers by this author
  • M Saint-Dizier

    Corresponding author
    1. ENVA, UMR1198, Maisons-Alfort, France
    2. AgroParisTech, UFR Génétique Elevage Reproduction, Paris Cedex 05, France
    • INRA, UMR1198 Biologie du Développement et Reproduction, Jouy-en-Josas, France
    Search for more papers by this author

Author's address (for correspondence): M Saint-Dizier, AgroParisTech, UFR Génétique Elevage Reproduction, 16 rue Claude Bernard, 75231 Paris Cedex 05, France. E-mail: stdizier@agroparistech.fr

Contents

In the bitch, oocyte maturation, sperm storage, fertilization and early embryo development take place within the oviducts under high and increasing circulating progesterone concentrations. To investigate the potential effects of progesterone on the canine oviduct, nuclear progesterone receptors (PR) were localized. Oviducts were collected by ovariectomy from adult Beagle bitches during anestrus, after the onset of proestrus but prior to the Luteinizing Hormone (LH) peak (Pre-LH), after the LH peak but before ovulation (Pre-ov) and on Days 1, 4 and 7 after ovulation (n = 3 bitches per stage). The cellular distribution of PR was studied by immunohistochemistry (IHC) in the ampulla, isthmus and tubal part of the utero-tubal junction (UTJ). Plasma progesterone and 17β-oestradiol were assayed on the day of surgery. PR were specifically expressed in the nuclei of epithelial, stromal and muscular cells in the ampulla, isthmus and UTJ. The IHC scores did not vary from one oviductal region to another. However, the epithelium displayed higher scores than the stroma at anestrus, Pre-ov, Days 4 and 7, and also higher scores than muscle at Days 4 and 7 (p < 0.05). Immunohistochemistry scores in the stroma and muscle decreased at Days 4 and 7 compared with previous stages (p < 0.05). Furthermore, muscular IHC scores were positively correlated with circulating 17β-oestradiol concentrations and negatively correlated with circulating progesterone concentrations (p < 0.05). In conclusion, PR were identified in the canine oviduct, with differences in expression between tissues and times around ovulation, suggesting that progesterone may regulate tubal functions and reproductive events in this species.

Ancillary