Seminal plasma does not aid in the transport of phenolsulfonphthalein across the uterotubal junction in mares.

This study tested the hypothesis that the presence of prostaglandin E2 in seminal plasma would aid in the transport of phenolsulfonphthalein (PSP) across the uterotubal junction. Five mares in estrus were inseminated during estrus with PSP dissolved in phosphate-buffered saline and during the subsequent estrus with PSP added to a standard insemination dose. Serum and urine samples were obtained at hours 0, 1, 2, and 3 following treatment and examined for the presence of PSP. Phenolsulfonphthalein could not be detected in any of the urine samples collected from mares following either treatment. None of the serum samples collected following intrauterine installation of PSP in PBS contained PSP. Phenolsulfonphthalein was detected in serum samples from 1 mare following insemination with semen containing PSP. Components in seminal plasma such as PGE2 did not facilitate the transport of PSP across the uterotubal junction as had been hypothesized.