Temporal and Tissue-Specific Expression of Prostaglandin Receptors EP2, EP3, EP4, FP, and Cyclooxygenases 1 and 2 in Uterus and Fetal Membranes during Bovine Pregnancy

Uteroplacental prostaglandins (PGs) play pivotal roles in maintenance and /or termination of pregnancy in mammals. Regulation of PG biosynthetic and signaling mechanisms in uteroplacental tissues during maintenance of pregnancy is largely unknown. In the present study, we have characterized the expression of PGE2 receptors (EP2, EP3, EP4), PGF2α receptor (FP), and cyclooxygenase (COX) types 1 and 2 in placentome caruncle (CAR), intercaruncle, and fetal membrane tissues during pregnancy in cattle. Pregnant bovine uteri were collected and classified into six groups covering the entire gestational length. The levels of expression of EP2, EP3, and FP mRNAs differ depending on tissues and days of gestation (days 250). EP4 mRNA was undetectable in all the tissues studied. The expression levels of PG receptor mRNAs were as follows: placentome CAR FP > EP2 >EP3, intercaruncle EP2 > EP3 ≥ FP, and fetal membranes EP3 ≥ EP2 ≫ FP. EP2 and EP3 expressions were modulated in uteroplacental tissues, depending o...