The In Vitro Effect of Steroid Hormones, Arachidonic Acid, and Kinases Inhibitors on , , , and Gene Expression in the Porcine Uterine Luminal Epithelial Cells during the Estrous Cycle.

Aquaporins (AQPs) are integral membrane proteins, which play an important role in water homeostasis in the uterus. According to the literature, the expression of aquaporins in reproductive structures depends on the local hormonal milieu. The current study investigated the effect of selected PKA kinase inhibitor H89 and MAPK kinase inhibitor PD98059, on the expression of , , , and , and steroid hormones (E), progesterone (P), and arachidonic acid (AA) in the porcine endometrium on days 18-20 and 2-4 of the estrous cycle (the follicular phase where estrogen and follicle-stimulating hormone (FSH) are secreted increasingly in preparation for estrus and the luteal phase where the ovarian follicles begin the process of luteinization with the formation of the corpus luteum and progesterone secretion, respectively). The luminal epithelial cells were incubated in vitro in the presence of the aforementioned factors. The expression of mRNA was determined by the quantitative real-time PCR technique. In general, in Experiment 1, steroid hormones significantly increased expression of , , and while arachidonic acid increased expression of and . On the other hand, MAPK kinase inhibitor significantly decreased the expression of and . In Experiment 2, E, P, or AA combined with kinase inhibitors differentially affected on AQPs expression. E in combination with PKA inhibitor significantly decreased expression of but E or P combined with this inhibitor increased the expression of and . On the contrary, E with PD98059 significantly increased and expression. Progesterone in combination with MAPK kinase inhibitor significantly downregulated the expression of and upregulated . Arachidonic acid mixed with H89 or PD98059 caused a decrease in the expression of and an increase of . The obtained results indicate that estradiol, progesterone, and arachidonic acid through PKA and MAPK signaling pathways regulate the expression of and in the porcine luminal epithelial cells in the periovulatory period.