Effect of boar seminal plasma on uterine and oviductal motility in oestrous gilts.

The effect of boar seminal plasma was tested on the muscular activity of the uterine horns and of the isthmic part of the oviducts in anaesthetized oestrous gilts. The motility was recorded by using balloon-tipped catheters placed in the middle part of the uterine horns and in the isthmus close to the uterotubal junction. The following test solutionis were used: sperm-free seminal plasma and isotonic glucose solution. In the isthmic part a test solution called OLEP was also used. OLEP is a buffer solution with electrolyte concentrations, pH and osmotic pressure similar to seminal plasma. Neither seminal plasma nor the buffers used affected the motility of the uterine horns. Seminal plasma decreased the spontaneous motility of the isthmus, mainly characterized by a reduced amplitude. No effect was, however, obtained with the different buffer solutions used. It is therefore supposed that an unidentified substance with relaxative effect on the isthmic muscle is present in the boar seminal plasma.