Implantation and Establishment of Pregnancy in the Pig

Geisert, Rodney D.; Johnson, Gregory A.; Burghardt, Robert C.

doi:10.1007/978-3-319-15856-3_8

Cited by 53 publications

(50 citation statements)

References 165 publications

(197 reference statements)

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“…The majority of these losses (20-30%) occur during the preimplantation period of development (Anderson 1978;Bolet 1986;Geisert and Schmitt 2002;Spencer 2013) at a time when the embryo is forming a blastocyst and secreting maternal recognition of pregnancy signals. Embryonic oestradiol (E 2 ) plays a crucial role in porcine maternal recognition of pregnancy signalling by shifting the secretion of prostaglandin F 2 a into the uterine lumen were it rapidly deteriorates; thus preventing transport to, and luteolysis of the corpus luteum via uterine vein-ovarian artery counter-current exchange (Bazer and Thatcher 1977;Zavy et al 1980;Geisert et al 1989;Stefa nczyk-Krzymowska et al 1990). …”

Section: Mechanisms By Which Heat-stressed Spermatozoa Can Affect Blamentioning

confidence: 99%

Revisiting summer infertility in the pig: could heat stress-induced sperm DNA damage negatively affect early embryo development?

Peña

Gummow

Parker³

et al. 2017

Anim. Prod. Sci.

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Abstract.Temperature is a crucial factor in mammalian spermatogenesis. The scrotum, pampiniform plexus, and cremaster and dartos muscles in mammals are specific adaptations to ensure sperm production in a regulated environment 4À6 C below internal body temperature. However, the limited endogenous antioxidant systems inherent in mammalian spermatozoa compounded by the loss of cytosolic repair mechanisms during spermatogenesis, make the DNA in these cells particularly vulnerable to oxidative damage. Boar sperm is likely to be more susceptible to the effects of heat stress and thus oxidative damage due to the relatively high unsaturated fatty acids in the plasma membrane, low antioxidant capacity in boar seminal plasma, and the boar's non-pendulous scrotum. Heat stress has a significant negative impact on reproductive performance in piggeries, which manifests as summer infertility and results in productivity losses that amount to millions of dollars. This problem is particularly prevalent in tropical and subtropical regions where ambient temperatures rise beyond the animal's zone of thermal comfort. Based on preliminary studies in the pig and other species, this article discusses whether heat stress could induce sufficient DNA damage in boar sperm to significantly contribute to the high rates of embryo loss and pregnancy failure observed in the sow during summer infertility. Heat stress-induced damage to sperm DNA can lead to disrupted expression of key developmental genes essential for the differentiation of early cell lineages, such as the trophectoderm, and can distort the timely formation of the blastocyst; resulting in a failure of implantation and ultimately pregnancy loss. Confirming such a link would prompt greater emphasis on boar management and strategies to mitigate summer infertility during periods of heat stress.

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Section: Mechanisms By Which Heat-stressed Spermatozoa Can Affect Blamentioning

confidence: 99%

Revisiting summer infertility in the pig: could heat stress-induced sperm DNA damage negatively affect early embryo development?

Peña

Gummow

Parker³

et al. 2017

Anim. Prod. Sci.

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“…It is obvious that the sustaining of proper embryo development and pregnancy depends on a complex cross-talk between the embryo and mother. In pigs, such communication begins on day 12 of pregnancy, when the fetus secretes an increased amount of estrogens (Geisert et al 1990). It is pos- sible that the cooperative action of embryonic and uterine E 2 stimulates endometrial PGE 2 synthesis (Waclawik 2011).…”

Section: Discussionmentioning

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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“…The maintenance and establishment of pregnancy in the pig requires a biphasic pattern of estrogen secretion, predominantly E 2 , on days 11-12 and again between days 15 and 25-30 of pregnancy (Geisert et al 1990). Additionally, a supporting role is played by increased amounts of PGE 2 originating from conceptuses and the endometrium prior to implantation (Waclawik and Ziecik 2007).…”

Section: Discussionmentioning

confidence: 99%

Effect of vaginal administration of prostaglandin E2 and/or 17β-estradiol on luteal function and histological characteristics of the cervix in cyclic pigs

Przygrodzka¹,

Andronowska²,

Janowski³

et al. 2014

Polish Journal of Veterinary Sciences

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The overall objective of this study was to examine the effect of vaginal administration of prostaglandin E 2 (PGE 2 ) and/or17β-estradiol (E 2 ) on luteal function maintenance and histological properties of the porcine cervix. For this purpose, crossbred gilts were divided into three groups (n=5 per group) supplied on days 11-16 of the estrous cycle with suppositories containing: (1) placebo (Group I, Control); (2) 0.4 mg of E 2 (Group II); (3) 0.4 mg of E 2 and 2 mg of PGE 2 (Group III). Blood samples were collected on days 11-19 of the estrous cycle to determine the concentration of progesterone (P 4 ). Additionally, to examine local effects of the hormones applied, segments from the uterine and vaginal parts of the cervix and from the ovaries were collected post-mortem. Prolonged luteal function and extended synthesis of P 4 were observed in 2 of 5 gilts receiving PGE 2 and E 2 simultaneously (Group III). Then, these gilts were subdivided into Group IIIA (n=2; presence of corpora lutea on the ovaries) and Group IIIB (n=3; lack of corpora lutea). Increased levels of plasma P 4 were observed in Group IIIA on days 15-19 compared to Group IIIB and on days 16-19 compared to Group I and Group II (P<0.05; P<0.01; P<0.001, respectively). In the cervix of gilts in Groups II and III, enlarged blood vessels in the lamina propria of both parts of the cervix were observed. Furthermore, in Group II the epithelium of the uterine part of the cervix was thicker (P<0.001). Our study confirmed the proposed luteotrophic/antiluteolytic actions of E 2 and PGE 2 applied intravaginally. These results are significant considering that very low doses of E 2 were used when compared to previous attempts. Despite the inadequate response to treatments in some of the gilts, the local effects of these hormones on the histological properties of the porcine cervix suggest that further improvements in the vaginal administration route might help to elaborate new methods for enhancing the luteal function in the pig.

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Implantation and Establishment of Pregnancy in the Pig

Cited by 53 publications

References 165 publications

Revisiting summer infertility in the pig: could heat stress-induced sperm DNA damage negatively affect early embryo development?

Revisiting summer infertility in the pig: could heat stress-induced sperm DNA damage negatively affect early embryo development?

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

Effect of vaginal administration of prostaglandin E2 and/or 17β-estradiol on luteal function and histological characteristics of the cervix in cyclic pigs

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