Quantitative characterization of prostaglandins in the uterus of early pregnant cattle

Abstract

Prostaglandins (PGs) are important regulators of reproductive processes including early embryonic development. We analyzed the most relevant PG in bovine uteri at different preimplantation pregnancy stages when compared with non-pregnant controls. Additionally, endometrium and trophoblast tissues were examined regarding specific enzymes and receptors involved in PG generation and function. Simmental heifers were artificially inseminated or received seminal plasma only. At days 12, 15, or 18, post-estrus uteri were flushed for PG determination by liquid chromatography-tandem mass spectrometry. Endometrium and trophoblast tissues were sampled for RNA extraction and quantitative real-time PCR analysis. At all days and points of time examined, the concentration of 6-keto PGF 1a (stable metabolite of PGI 2 ) was predominant followed by PGF 2a OPGE 2 OPGD 2 zTXB 2 (stable metabolite of TXA 2 ). At days 15 and 18, PG increased from overall low levels at day 12, with a much more pronounced increase during pregnancy. The PGF 2a /PGE 2 ratio was not influenced by status. The highest PG concentration was measured at day 15 with 6-keto PGF 1a (6.4 ng/ml) followed by PGF 2a (1.1 ng/ml) and PGE 2 (0.3 ng/ml). Minor changes in endometrial PG biosynthesis enzymes occurred due to pregnancy. Trophoblasts revealed high transcript abundance of general and specific PG synthases contributing to uterine PG. As PGI 2 and PGF 2a receptors were abundantly expressed by the trophoblast, abundant amounts of PGI 2 and PGF 2a in the uterine lumen point towards an essential role of PG for the developing embryo. High amounts of PG other than PGE 2 in the preimplantation uterus may be essential rather than detrimental for successful reproduction.

Peroxisome proliferator-activated receptors in the regulation of female reproductive functions

“…In the endometrium of pregnant cows, a lack of differences in PPARg mRNA level was noted [51], while in ovine endometrium the expression of PPARb stayed at a constant level on days 7-17 (peri-implantation period), PPARg declined from days 7 to 17 and PPARg peaked www.fhc.viamedica.pl first at day 9 and then on day 17 [49]. Differences in PPARb and PPARg gene expression were also reported in porcine endometrium [52].…”

Lipopolysaccharide enhances apoptosis of corpus luteum in isolated perfused bovine ovaries in vitro

“…Therefore, total RNA from luteal tissue samples was isolated and reverse-transcribed as described (Ulbrich et al 2009) and luteal mRNA expression was determined in a two-step quantitative real-time PCR (qPCR). The qPCR was performed using the CFX384 Real-Time PCR Detection System (Bio-Rad, Munich, Germany) and the SsoFast EvaGreen Supermix (Bio-Rad).…”

Novel insights into the mechanisms of pregnancy establishment: regulation of prostaglandin synthesis and signaling in the pig

“…For example, in rodents and ruminants, prostacyclin is considered to be involved in implantation and signaling pathways between the uterus and the conceptus during peri-implantation period, respectively (Cammas et al 2006, Kennedy et al 2007, Ulbrich et al 2009). However, in the pig, the role of prostacyclin in the early pregnancy still remains to be elucidated.…”