Intraluminal Pressure Variations in the Isthmus of the Porcine Oviduct after Intrauterine Insemination with Saline,Oestrogen Solution or Boar Seminal Plasma

The purpose of this study was to investigate if an intrauterine deposition of saline, boar seminal plasma, or an oestrogen solution containing 11.5 µg oestrogens affected the intraluminal pressure in the isthmus of the oviduct in unrestrained gilts. In order to monitor variations in intraluminal pressure, 2 ultra-miniature pressure sensors, located at 2 different points along the same isthmus were used. After an initial recording period, either saline, boar seminal plasma, or the oestrogen solution was deposited directly into the uterus. Intraluminal pressure recordings were conducted up to 6 h after insemination, and blood samples, for monitoring oestradiol-17B and 15-ketodihydroprostaglandin F_2α levels, were collected. None of the inseminates had any consistent effect on the intraluminal pressure in the porcine oviduct. After deposition of the oestrogen solution, increases in the circulating levels of both oestradiol-17B and 15-ketodihydropro- staglandin F_2α were seen.