Prostaglandin E2 and F2α receptors in the human Fallopian tube before and after mifepristone treatment

Prostaglandins are associated with several reproductive processes in addition to their effects on the vascular system and muscular contractility. The aim of this study was to gain information about the localization of the receptors for PGE2 (EP1–EP4) and PGF2α (FP) in the human Fallopian tube and their regulation following treatment with mifepristone. Sixteen healthy fertile women received a single dose of 200 mg mifepristone or placebo immediately after ovulation (LH+2). Laparoscopic sterilization was performed on days LH+4 to LH+6. Biopsies were taken from the Fallopian tubes bilaterally. The expression of EP1, EP2, EP3, EP4 and FP was analysed using immunohistochemistry and RT–PCR. The co-localization of prostaglandin receptors and c-kit or e‐nos was analysed using confocal microscopy. The effect of progesterone, mifepristone and prostaglandin on tubal contractility was studied. The presence of EP1–EP4 and FP in the Fallopian tube was detected using immunostaining. The receptors were expressed in serosal cells, luminal epithelial cells, and the muscular wall and vessels of the Fallopian tube. Co-localization studies showed that the endothelial cells stained positive for EP1–EP4 and FP and that co-localization was seen for EP4 and c-kit. Decreased contractility was seen after progesterone treatment, whereas increased contractility was seen after PGF2α and PGE2 treatment. These data suggest that both the transport of the embryo and the communication between the embryo and the Fallopian tube involve the action of prostaglandins through EP and FP receptors in addition to the effect of prostaglandins on the vascular system and muscular contractility.