Secretion of estradiol-17β by porcine endometrium and myometrium during early pregnancy and luteolysis

Franczak, Anita; Kotwica, Genowefa

doi:10.1016/j.theriogenology.2007.09.023

Cited by 54 publications

(34 citation statements)

References 34 publications

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“…Whether or not FSH contributes to influence luteal function remains speculation. If we were to accept previous reports that steroid treatments in pigs [8,9] or GnRH in horses [30,31] benefit pregnancy outcome, other routes of GnRH mediation could also be evident, such as those influencing processes of uterine estrogen synthesis [32], endometrial angiogenesis, utero-ovarian counter-current transfer [33] and P4 dependent immunomodulation [34,35]. Furthermore, direct effects of GnRH on ovarian luteal cells [36] and on uterine tissues mediated by extrapituitary receptors should be recognized [37,38].…”

Section: Gnrh Agonist Effects In Pregnant Giltsmentioning

confidence: 96%

Endocrine Effects of GnRH Agonist Application to Early Pregnant Gilts

Brüssow

Schneider

Wollenhaupt

et al. 2011

Journal of Reproduction and Development

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Abstract. The hypothesis of the present study was that a GnRH agonist application at early pregnancy would alter the pattern of the key reproductive hormones LH and FSH, and subsequently that of estradiol (E2) and especially progesterone (P4), and improve the conditions for embryo survival in early pregnant gilts. Therefore, the endocrine effects of a GnRH agonist (GnRHa) application to gilts (n=11 GnRHa treated, n=9 saline Controls) were studied in blood samples from the Vena cava caudalis. GnRHa injected on Day 12 after insemination induced elevated (P<0.01) LH and FSH levels for at least 180 min. However, subsequent LH concentrations were not altered up to Day 21 of pregnancy. LH pulse number, estimated in 6-h period samples on Days 13, 15 and 17, was not influenced by treatment and pregnancy. LH pulse amplitude was decreased (P<0.05) on Days 13 to 17 in pregnant gilts of both groups, but not in nonpregnant animals. In pregnant GnRHa-treated gilts, the basal LH level was elevated compared with the Controls (P<0.01). Additionally, differences (P<0.05) in basal LH were present between the pregnant and nonpregnant animals. The P4 and E2 secretion pattern was not affected by GnRHa. P4 concentrations increased (P<0.01) from Day 10 to Day 14 regardless of the treatment. P4 revealed a pulse-like pattern, but without a definite relation to the LH pulse characteristics. Also, pregnancy rate (73 vs. 67%) and the number of fetuses (12.8 ± 2.3 vs. 11.6 ± 2.3) were unaffected in the treated and Control gilts, respectively. The present study did not confirm the initial hypothesis that a GnRHamediated LH effect could alter ovarian steroid secretion and favorably support early embryo development and pregnancy outcome. Key words: GnRH-agonist, LH, Pig, Pregnancy, Progesterone (J. Reprod. Dev. 57: [242][243][244][245][246][247][248] 2011) rogesterone from the developing corpus luteum (CL) is the most important driver of endometrial secretion and receptivity for early conceptus development and implantation in pigs [1,2]. About 30% of porcine conceptuses are lost during the peri-implantation period [3], and this period is susceptible to a lack of P4. It has been shown that a concentration of 4 ng/ml P4 in peripheral blood appears to be minimum required for maintenance of pregnancy [4]. Attempts have been undertaken to improve pregnancy rate or reduce pregnancy losses in pigs by steroid or gonadotropin application [5][6][7]. Since steroid treatment may improve litter size [8,9], the question is whether luteal P4 secretion can be enhanced by GnRH-induced LH stimulation. This is because LH is considered to be essential in pigs for support of luteal P4 production and pregnancy outcome as demonstrated by passive immunization with anti-LH serum or blockage of LH secretion and regulation of ovarian function by a GnRH antagonist [10,11].The hypothesis of the present study was that a single GnRH agonist application, given on Day 12 after insemination, would alter the pattern of the key reproductive hormones LH and FSH, and subsequentl...

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Section: Gnrh Agonist Effects In Pregnant Giltsmentioning

confidence: 96%

Endocrine Effects of GnRH Agonist Application to Early Pregnant Gilts

Brüssow

Schneider

Wollenhaupt

et al. 2011

Journal of Reproduction and Development

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“…The pattern of OTR gene expression in the endometrium is distinct from that of the adjacent myometrium. We suppose that estrogens, which are produced not only by porcine embryos during maternal recognition of pregnancy [33], but also originate, in large amounts, from the pregnant endometrium [56,57], may act as upregulators of OTR gene expression in the pregnant part of the endometrium. Estrogens may directly influence the OTR gene and increase OTR mRNA [58].…”

Section: Embryo Presence and Uterine Secretion Of Prostaglandinsmentioning

confidence: 99%

“…Estrogens may directly influence the OTR gene and increase OTR mRNA [58]. On the other hand, during early pregnancy the myometrium has been found to produce diminished amounts of E2 than the endometrium [56]. Thus, the level of OTR mRNA might be decreased in the myometrium.…”

Section: Embryo Presence and Uterine Secretion Of Prostaglandinsmentioning

confidence: 99%

Local and Systemic Effects of Embryos on Uterine Tissues During Early Pregnancy in Pigs

Franczak

Bogacki

2009

J. Reprod. Dev.

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Abstract. In the pig, the periimplantation period is critical for successful establishment of pregnancy. We studied the influence of embryos on oxytocin (OT) and progesterone (P4) regulated endometrial and myometrial secretion of 1) luteotrophic prostaglandin E2 (PGE2) and 2) luteolytic prostaglandin F2α and its metabolite (PGFM) on days 12-14 of pregnancy in pigs. We used unilaterally pregnant pigs created by a surgical procedure in which one uterine horn remained intact and the second horn was cut transversely so that part of the horn was detached from the uterine body. The animals were divided into two groups, inseminated gilts (days 12-14 of pregnancy, n=6) and uninseminated cyclic gilts, which were used as controls (days 12-14 of estrous cycle, n=5). Embryos developed only in the patent part of the uterus and not in the occluded horn. The abundance of OTR mRNA was increased in the endometrium and decreased in the myometrium of the gravid uterine horn in the pregnant pigs compared with the non-gravid uterine horn or either uterine horn in the cyclic pigs, indicative of a local effect of the conceptus. The presence of embryos in the uterine horn during the periimplantation period determines endometrial metabolism of PGF2α and the local response of the endometrium to OT and P4. OT stimulates PGF2α secretion and PGFM accumulation in endometrial cultures only from the non-gravid uterine horn and controls PGE2 secretion from the endometrium and myometrium in the pregnant gilts. The results indicate a more systemic affect of pregnancy on the uterine response to OT and a possibly the local effect of the conceptus in promoting progesterone's inhibition of OT-stimulated PGE2 secretion and uterine metabolism of PGF2α. Key words: Embryos, Oxytocin, Pigs, Progesterone, Prostaglandin E2, Prostaglandin F2α and its metabolite, Uterus (J. Reprod. Dev. 55: [262][263][264][265][266][267][268][269][270][271][272] 2009) rostaglandins (PG) produced in the uterus and corpus luteum are necessary for successful reproduction [1,2]. Oxytocin, acting through oxytocin receptors (OTR) in the endometrium and myometrium, is involved in the control of prostaglandin F2α (PGF2α) and prostaglandin E2 (PGE2) secretion in pigs [3][4][5][6][7][8]. Prostaglandin F2α is responsible for luteal regression in non-pregnant pigs [1,9], while prostaglandin E2 acts as a luteotrophic and antiluteolytic factor that promotes maintenance of the corpus luteum during early pregnancy in pigs [10,11].Alteration of PG secretion by OT is implicated in maternal recognition of pregnancy in pigs [12][13][14]. Moreover, OT stimulates myometrial secretion of PGF2α and PGE2 as well as the contractile activity of the porcine myometrium during early pregnancy [8,15,16]. The uterine response to OT depends on expression of OTR mRNA and protein [7,[17][18][19] and on generation of the second messengers inositol triposhate and diacyloglycerol [7,18,20,21]. OT also stimulates PGF2α secretion from the bovine endometrium through a previously discussed signaling pathway [22][2...

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“…In addition, changes in the expression of 3β-hydroxysteroid dehydrogenase/Δ(5)-Δ(4) isomerase (3β-HSD), the gene involved in the P 4 production, were demonstrated mostly during the estrous cycle . Enhanced amounts of estradiol (E 2 ) released by the endometrial explants were noted during early pregnancy compared with luteolysis period (Franczak and Kotwica 2008). The above results might suggest that the porcine endometrium is a significant source of steroids and may supplement steroidogenesis by the conceptus during maternal recognition of pregnancy (Franczak and Kotwica 2008).…”

Section: Introductionmentioning

confidence: 93%

“…Recently, it has been demonstrated that the uterus is able to produce steroid hormones de novo in both early pregnant and cyclic pigs (Franczak and Kotwica 2008;Franczak et al 2013). Interestingly, their endometrial expression varied, depending on physiological status of animals.…”

Section: Introductionmentioning

confidence: 99%

Peroxisome proliferator activated receptor ligands affect porcine endometrial steroids production during the estrous cycle and early pregnancy: an in vitro study

Kurzyńska¹,

Bogacki²,

Chojnowska³

et al. 2016

CZECH J ANIM SCI

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AbstrAct:In the present study, we investigated the effect of PPAR ligands on progesterone (P 4 ) and 17β-estradiol (E 2 ) secretion, as well as 3β-hydroxysteroid dehydrogenase/Δ(5)-Δ(4) isomerase (3β-HSD) mRNA expression, in porcine endometrial slices collected on days 10-12 and 14-16 of the estrous cycle or early pregnancy. The explants were incubated in vitro for 6 h in the presence of PPARα ligands -WY-14643 (agonist) and MK 886 (antagonist); PPARβ ligands -L-165041 (agonist) and GW 9662 (antagonist); PPARγ ligands -15d-prostaglandin J 2 and rosiglitazone (agonists) and T0070907 (antagonist). During the estrous cycle, all PPAR ligands inhibited P 4 secretion during the mid-luteal phase (days 10-12). During early pregnancy, a stimulatory effect of PPARα agonist was observed during maternal recognition of pregnancy (days 10-12), while an inhibitory effect was observed at the beginning of implantation (days 14-16). PPAR ligands inhibited the expression of 3β-HSD mRNA on days 14-16 of the estrous cycle (β and γ isoforms) or pregnancy (α, β, γ isoforms) but did not affect gene expression on days 10-12 of the estrous cycle or early pregnancy. An inhibitory effect of PPARα, PPARγ, and PPARβ on E 2 secretion was observed during maternal recognition of pregnancy, but a stimulatory effect was observed during mid-(γ isoform) or late-luteal (β isoform) phases of the estrous cycle. Our study indicates, for the first time, that PPARs are engaged in P 4 and E 2 production in porcine endometrium. It is possible that the diverse receptivity of endometrial tissue to the PPAR ligands can be associated with the reproductive status of gilts.

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Secretion of estradiol-17β by porcine endometrium and myometrium during early pregnancy and luteolysis

Cited by 54 publications

References 34 publications

Endocrine Effects of GnRH Agonist Application to Early Pregnant Gilts

Endocrine Effects of GnRH Agonist Application to Early Pregnant Gilts

Local and Systemic Effects of Embryos on Uterine Tissues During Early Pregnancy in Pigs

Peroxisome proliferator activated receptor ligands affect porcine endometrial steroids production during the estrous cycle and early pregnancy: an in vitro study

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