Regulation of prostaglandin F2  and E receptor mRNA by prostaglandin F2  in ovine corpora lutea

Abstract

Prostaglandins regulate many physiological functions, including reproduction, by binding to specific plasma membrane receptors. In this study we evaluated the regulation of PGF2 alpha (FP) and PGE (EP3 subtype) receptors in ovine corpora lutea. In the first study, tissue distribution of FP and EP3 receptors was evaluated in 13 ovine tissues. FP receptor mRNA was present in 100-fold higher concentration in corpora lutea than in other tissues. Similarly, [3H]PGF2 alpha binding was much greater in luteal plasma membranes than in membranes from other tissues. In contrast, EP3 receptor mRNA was more uniformly distributed, with high concentrations in adrenal medulla, inner myometrium, kidney medulla and heart. The distribution of [3H]PGE1 binding was generally similar to EP3 mRNA, with the exception that ovarian stroma, endometrium and outer myometrium had high [3H]PGE1 binding but low concentrations of EP3 receptor mRNA. The second study evaluated the action of PGF2 alpha on luteal mRNA encoding FP and EP3 receptors. Ewes had PGF2 alpha or saline infused into the ovarian artery and corpora lutea were removed at 0, 1, 4, 12 and 24 h. FP receptor mRNA decreased by 50% at 12 and 24 h after infusion with PGF2 alpha, whereas EP3 mRNA was unchanged. Treatment of large luteal cells with PGF2 alpha, phorbol didecanoate (protein kinase C activator), or ionomycin (calcium ionophore) decreased FP receptor mRNA after 24 h (P < 0.05). Glyceraldehyde 3-phosphate dehydrogenase mRNA was not changed by any treatment. These results show that EP3 receptors are expressed in many tissues and expression is not regulated by PGF2 alpha. In contrast, FP receptors are primarily expressed in corpora lutea and expression is inhibited by PGF2 alpha.

Actions of Prostaglandin F2α and Prolactin on Intercellular Adhesion Molecule-1 Expression and Monocyte/Macrophage Accumulation in the Rat Corpus Luteum1

“…Indeed, inhibition of steroidogenesis does not initiate luteal regression or augment PRL-induced luteal regression in the hypophysectomized rat [58]. Similar to the current study, inhibition of FP receptor mRNA by PGF has been reported in sheep, cow, and human cells [59][60][61][62][63], and PGF binding to rat luteal cells is reduced following PGF treatment [64]. In contrast, Olofsson and colleagues [65] report that PGF increases FP receptor mRNA concentrations in rats.…”

Characterization of a Rabbit Kidney Prostaglandin F2α Receptor Exhibiting Gi-restricted Signaling That Inhibits Water Absorption in the Collecting Duct

“…Tissue Distribution of Rabbit FP mRNA-RNase protection assays on mRNA harvested from different rabbit tissues (n ϭ 3-4 for each tissue) revealed that FP mRNA was highly expressed in the ovary as seen in other species including sheep and humans (8,(23)(24)(25)(26). In addition, lower levels of FP mRNA expression were detected in the kidney with barely detectable expression in other tissues tested including heart, liver, spleen, lung, brain, stomach, large intestine, and aorta (Fig.…”

Intraluteal Prostaglandin Biosynthesis and Signaling Are Selectively Directed Towards PGF2alpha During Luteolysis but Towards PGE2 During the Establishment of Pregnancy in Sheep1

“…It has been shown that parenteral administration of PGF 2a decreased PTGFR mRNA within 12-24 h on Days 10-14 of the estrous cycle in sheep [60,61]. Activation of FP in turn activates PKC, inositol 1,4,5-triphosphate (IP3), and Ca2 þ cell signaling pathways [4] and interacts with multiple intracellular cell signaling pathways in the luteal cells in sheep and cows [13,62,63].…”