Luteogenic and luteotropic effects of eCG during pregnancy in the mare.
Abstract: The role of eCG during pregnancy was evaluated through the study of the temporal relationships between changes in eCG and progesterone concentrations and the formation of supplementary corpora lutea (SCL) in mares impregnated with donkey semen (mule pregnancies) or with horse semen (equine pregnancies). Concentrations of eCG were higher (p<0.01) in equine than in mule pregnancies between weeks 6.5 and 13. Progesterone concentrations were higher in equine than in mule pregnancies between weeks 9 and 17. All animals developed at least one SCL, but more SCL accumulated during equine pregnancies than during mule pregnancies (1.9 ± 0.2 vs 1.2 ± 0.1; p<0.01). In equine pregnancies, the mares that formed a second SCL had higher eCG concentrations (p<0.05) during the two weeks preceding its formation than those mares remaining with only one SCL. Mares that formed a third SCL had higher (p<0.5) eCG levels than those remaining with one or two SCL. Mares with equine pregnancies that formed three SCL had higher progesterone concentrations (p0.05). It is concluded that eCG stimulates both the development of new SCL and the function of existing CL. While these effects are clearly expressed in mares impregnated by horses, the low eCG concentrations during mule pregnancies reduce the impact of this hormone on CL formation and function.
Copyright © 2012. Published by Elsevier B.V.
Publication Date: 2012-01-21 PubMed ID: 22325968DOI: 10.1016/j.anireprosci.2012.01.001Google Scholar: Lookup
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- Journal Article
- Research Support
- Non-U.S. Gov't
Summary
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The research mainly analyzes the role of a hormone called eCG during pregnancy in mares (female horses) and how it influences the concentration of a second hormone, progesterone, and the formation of supplementary corpora lutea (SCL). The study finds that the mares impregnated with horse semen have greater eCG concentrations and therefore higher progesterone levels and form more SCL, as compared to mares impregnated with donkey semen.
Hormonal Differences between Equine and Mule Pregnancies
- The study found clear differences in the hormone levels of equine and mule pregnancies (mares impregnated by horses and donkeys, respectively). In particular, the concentrations of eCG (equine chorionic gonadotropin), a hormone involved in pregnancy, were significantly higher during weeks 6.5 and 13 of equine pregnancies compared to mule ones.
- The concentration of another hormone, progesterone, was also found to be higher in equine pregnancies during weeks 9 and 17.
Supplementary Corpora Lutea (SCL) Formation
- Mare pregnancies, whether equine or mule, saw the development of at least one Supplementary Corpora Lutea (SCL), a structure developed after ovulation that contributes to the maintenance of pregnancy.
- Nevertheless, a greater number of SCLs were developed during equine pregnancies as opposed to mule pregnancies.
- Mares with equine pregnancies that developed a second or third SCL showed higher eCG concentrations in the two weeks prior to its formation compared to those that developed only one SCL.
- Equine pregnancies that developed as many as three SCL also presented higher progesterone concentrations. This variance was not observed in mule pregnancies, irrespective of the number of SCLs developed.
Link Between eCG, SCL development, and Progesterone Concentration
- The study concluded that the eCG hormone stimulates the development of SCL as well as the function of existing corpora lutea (structures developed after ovulation).
- This effect is markedly higher in horses, potentially because eCG concentrations during mule pregnancies are lower, which, in turn, lessens the hormone’s impact on the formation and function of corpora lutea.
Cite This Article
APA
Boeta M, Zarco L.
(2012).
Luteogenic and luteotropic effects of eCG during pregnancy in the mare.
Anim Reprod Sci, 130(1-2), 57-62.
https://doi.org/10.1016/j.anireprosci.2012.01.001 Publication
Researcher Affiliations
- Departamento de Reproducción, Facultad de Medicina Veterinaria y Zootecnia, Universidad Nacional Autónoma de México, Ciudad Universitaria, DF, Mexico.
MeSH Terms
- Animals
- Chorionic Gonadotropin / blood
- Corpus Luteum / physiology
- Equidae
- Female
- Horses / physiology
- Luteinizing Hormone / metabolism
- Male
- Pregnancy
- Progesterone / blood
- Semen / physiology
Citations
This article has been cited 6 times.- Byambaragchaa M, Choi SH, Joo HE, Kim SG, Kim YJ, Park GE, Kang MH, Min KS. Specific Biological Activity of Equine Chorionic Gonadotropin (eCG) Glycosylation Sites in Cells Expressing Equine Luteinizing Hormone/CG (eLH/CG) Receptor.. Dev Reprod 2021 Dec;25(4):199-211.
- Lee SY, Byambaragchaa M, Choi SH, Kang HJ, Kang MH, Min KS. Roles of N-linked and O-linked glycosylation sites in the activity of equine chorionic gonadotropin in cells expressing rat luteinizing hormone/chorionic gonadotropin receptor and follicle-stimulating hormone receptor.. BMC Biotechnol 2021 Sep 5;21(1):52.
- Min KS, Park JJ, Lee SY, Byambaragchaa M, Kang MH. Comparative gene expression profiling of mouse ovaries upon stimulation with natural equine chorionic gonadotropin (N-eCG) and tethered recombinant-eCG (R-eCG).. BMC Biotechnol 2020 Nov 11;20(1):59.
- Hannan MA, Haneda S, Murata K, Takeuchi S, Cheong SH, Nambo Y. Birth of first foals through embryo transfer after artificial insemination using frozen semen in Japan.. J Reprod Dev 2020 Apr 10;66(2):193-197.
- Min KS, Park JJ, Byambaragchaa M, Kang MH. Characterization of tethered equine chorionic gonadotropin and its deglycosylated mutants by ovulation stimulation in mice.. BMC Biotechnol 2019 Aug 13;19(1):60.
- Park JJ, Seong HK, Kim JS, Munkhzaya B, Kang MH, Min KS. Internalization of Rat FSH and LH/CG Receptors by rec-eCG in CHO-K1 Cells.. Dev Reprod 2017 Jun;21(2):111-120.
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