Regulation of muscular contractions in the human Fallopian tube through prostaglandins and progestagens

Abstract

BACKGROUND: Transport of gametes and embryos is an important function of the Fallopian tube. Both muscular contractions and cilia activity are involved in the transportation. Prostaglandins (PGs) are known mediators of muscular contractility. PG receptors have previously been demonstrated in the human Fallopian tube. The aim was to study the effect of PGs and progestagens, antiprogestin, hCG and oxytocin on muscular contractions in the human Fallopian tube, and the hormonal regulation of PG receptors. METHODS: Twenty-two healthy women operated for benign causes were included in the study. The ampullary-isthmic junction of the Fallopian tubes was excised and used for in vitro contractility studies. The effect of PGE1, PGE2, PGF2α, progesterone, mifepristone, levonorgestrel, oxytocin and hCG on contractility was studied. Explants of Fallopian tubes were cultured for 24 h to study the effect of progestagens and hCG on the expression of PG receptors using immunohistochemistry and real-time PCR. RESULTS: Muscular contractions increased after treatment with PGF2α and PGE 2 (P < 0.05). The contractions decreased after PGE1, progesterone, levonorgestrel, mifepristone, oxytocin and hCG (P < 0.05). In tubal explant studies, relative mRNA expression of EP1, EP2, EP3 and FP increased after levonorgestrel treatment (P < 0.05). Mifepristone and levonorgestrel treatment increased immunostaining intensity of EP1 and EP2 protein, in lumen, muscle and vessels. Progesterone and mifepristone increased immunostaining of FP in vessels. CONCLUSIONS: These data suggest that the transport of gametes and embryos involves the action of PGs, progesterone, oxytocin and hCG on muscular contractility. © The Author 2008. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved.