Effects of prostaglandin E and F receptor agonists in vivo on luteal function in ewes

Effects of intraluteal implants of prostaglandin E1 or E2 on angiogenic growth factors in luteal tissue of Angus and Brahman cows

“…However, the FP prostanoid receptor was decreased on Day 19 in both Angus and Brahman vehicle controls, whereas PGE 1 or PGE 2 on Day 19 in these same cows increased mRNA for the prostanoid FP and EP3B receptors and decreased mRNA for prostanoid EP2 and EP4 receptors [14]. An EP3 prostanoid receptor agonist in vivo is as effective as PGF 2a in causing luteolysis [15]. Data in ewes also support PGE 1 or PGE 2 as antiluteolysins to prevent luteolysis.…”

Control of the Ovarian Cycle of the Sheep

“…Interferon tau, produced by the trophoblast of the conceptus, is a major signal in the maternal recognition process, 264,273 and evidence for the involvement of prostaglandins E 1 and E 2 in this process has existed since the 1970s (reviewed by Weems et al [274][275][276]. 281 In that same study, the luteolytic action of PGF 2α was mediated via prostaglandin F and EP3 receptors. This possibility initially arose from observations that intrauterine and subcutaneous injections of interferon tau were equally effective in inducing the expression of two proteins in the corpus luteum.…”

Effects of LPA2R, LPA3R, or EP4R agonists on luteal or endometrial function in vivo or in vitro and sirtuin or EP1R, EP2R, EP3R or EP4R agonists on endometrial secretion of PGE and PGF2α in vitro

“…However, an EP1R (17 PT-PGE 2 ), EP3R (Sulprostone), and an EP4R (CAY 10580) agonist increased ovine caruncular endometrial PGE secretion in vitro, while two EP2R agonists (Butaprost or 19-OH-PGE2) did not increase caruncular endometrial PGE secretion. These same two EP2R agonists given via the same route increased ovine circulating progesterone in vivo ,while Sulprostone an EP3R agonist decreased circulating progesterone [22]. Thus, the endometrial EP4R agonist (CAY10580) may be more important than caruncular endometrial EP2R to regulate caruncular endometrial PGE secretion in the ewe.…”

“…An EP2R agonist given into the interstitial tissue of the ovarian vascular pedicle adjacent to the lutealcontaining ovary increased mRNA expression of luteal LHR and occupied and unoccupied LHR, while an EP3R agonist or PGF 2α decreased circulating progesterone, luteal mRNA for LH receptors, and luteal unoccupied and occupied LHR [22]. An EP1R agonist had no effect on luteal function in vivo in ewes [22]. In cows, intraluteal silastic implants inserted on Day-13 postestrus containing PGE 1 or PGE prevented loss of circulating progesterone, luteal mRNA expression for LHR and luteal unoccupied and occupied LHR on Day-19 postestrus, [23}.However, PGE or PGE 2 upregulated luteal mRNA expression of FPR, but luteal mRNA expression for EP2R and EP4R in these same cows was downregulated by PGE 1 or PGE 2 [24].…”

“…EP2R and EP4R agonists increase cAMP [21], the second messenger for LHstimulated small luteal cell progesterone secretion [19]. An EP2R agonist given into the interstitial tissue of the ovarian vascular pedicle adjacent to the lutealcontaining ovary increased mRNA expression of luteal LHR and occupied and unoccupied LHR, while an EP3R agonist or PGF 2α decreased circulating progesterone, luteal mRNA for LH receptors, and luteal unoccupied and occupied LHR [22]. An EP1R agonist had no effect on luteal function in vivo in ewes [22].…”