Effects of orexin A on PTGS2, PTGES, CBR1 and PGFS mRNA transcript abundances and prostaglandin E2 and F2α concentrations in culture medium of pig uterine explants collected during early gestation and the estrogenic cycle

Abstract

In this study, aims were to evaluate orexin A (OXA) effects on mRNA abundance of important enzymes involved in prostaglandin production, such as cyclooxygenase 2 (PTGS2), microsomal PGE₂ synthase-1 (PTGES), PGF_2α synthase (PGFS) and carbonyl reductase 1 (CBR1), as well as prostaglandin E₂ (PGE₂) and F_2α (PGF_2α) culture medium concentrations for endometrial and myometrial explants. Tissues were collected from gilts during specific phases of the estrogenic cycle or early gestational period. There were greater concentrations of PGE₂ with OXA treatments of endometrial tissues collected on days 12-13 and 27-28, as well as PGF_2α on days 10-11 of the gestational period. The PGF_2α concentrations were less in tissues collected on days 27-28 of the gestational period. The OXA treatments resulted in lesser concentrations of PGE₂ from myometrial tissues collected on days 10-11 and greater PGF_2α on days 10-11 of the gestational period and 10-11 of the estrogenic cycle. Effects of OXA may occur due to actions at PTGS2, PTGES, PGFS and CBR1 genes because mRNA abundances for proteins encoded by these genes were affected by OXA. Results indicate there is an OXA effect on mRNA abundances and prostaglandin culture medium concentrations of uterine tissue collected at different stages of the gestational period or estrogenic cycle using different doses of OXA. It, therefore, is concluded OXA may affect de novo synthesis and secretion of PGE₂ and PGF_2α in the uterus of pigs.

Keywords: Early pregnancy; Orexin; Pig; Prostaglandins; Uterus.