Production of free estrogens and estrogen conjugates by the preimplantation equine embryo.
Abstract: In vitro production of free estrogens and estrogen conjugates by intact Day 12.5, 13.5 and 14.5 equine embryos was measured at 2-h intervals over a 24-h culture period. Production of free estrogens was higher for Day 14.5 than Day 12.5 embryos. Differences in production of conjugated estrogens were not significant, but a trend toward increased production with increased age of embryo was apparent. No trend toward increased free and conjugated estrogen production per cell was observed with age. Embryo diameter and number of cells increased with age but varied considerably within groups. The amount of free and conjugated estrogens measured in blastocoelic fluid did not decrease over the 24-h culture period, suggesting that estrogens detected in culture medium were produced by the embryo and not the result of leakage of maternal estrogen from the blastocoele. The results of this study support previous results that estrogen production increases with development of equine embryos. This increase in estrogen production appears to be more closely associated with the diameter of the embryo, and hence its number of cells, than with increased intracellular steroidogenic activity.
Publication Date: 1997-01-15 PubMed ID: 16727998DOI: 10.1016/s0093-691x(97)00004-6Google Scholar: Lookup
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- Journal Article
Summary
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The research article investigates the in vitro production of unbound estrogens and estrogen conjugates by preimplantation horse embryos (Days 12.5, 13.5, and 14.5), and finds an increasing trend of estrogen production with the age and size of the embryo.
Objective of Research
- The study aims to understand the production of free (unbound) estrogens and estrogen conjugates by preimplantation horse embryos in vitro (lab environment), and to see whether the production correlates with the age and size of the embryo.
Methodology
- Preimplantation horse embryos on Days 12.5, 13.5, and 14.5 were cultured for 24 hours, and their production of estrogens and estrogen conjugates was measured every 2 hours.
- The diameters and cell counts of the embryos were also tracked to see if these factors had any influence on estrogen production.
Findings
- Day 14.5 embryos produced more unbound estrogens than Day 12.5 embryos.
- While the difference in production of conjugated estrogens was not statistically significant across days, there was a visible pattern of increased production with the age of the embryo.
- No increasing pattern was found in the per-cell production of both free and conjugated estrogens with embryo age.
- Both embryo size and cell count increased with age, but there was substantial variation within each day’s group.
- No decrease in estrogen levels was observed in the blastocoelic fluid (fluid within the blastocoele, an early embryonic structure) over the culture period, which led the researchers to conclude that the estrogens detected in the culture medium were genuinely produced by the embryo, and not merely a leakage of maternal estrogen from the blastocoele.
Conclusions
- The results reinforced earlier findings that showed an increase in estrogen production with advancing developmental stages of equine embryos.
- The rising trend in estrogen production was found to be more strongly correlated with the embryo’s diameter (and therefore number of cells) rather than any increase in its intrinsic steroid hormone-synthesizing activity.
Cite This Article
APA
Choi SJ, Anderson GB, Roser JF.
(1997).
Production of free estrogens and estrogen conjugates by the preimplantation equine embryo.
Theriogenology, 47(2), 457-466.
https://doi.org/10.1016/s0093-691x(97)00004-6 Publication
Researcher Affiliations
- Department of Animal Science, University of California, Davis, CA 95616, USA.
Citations
This article has been cited 3 times.- Vegas AR, Podico G, Canisso IF, Bollwein H, Fröhlich T, Bauersachs S, Almiñana C. Dynamic regulation of the transcriptome and proteome of the equine embryo during maternal recognition of pregnancy.. FASEB Bioadv 2022 Dec;4(12):775-797.
- Lawson EF, Grupen CG, Baker MA, Aitken RJ, Swegen A, Pollard CL, Gibb Z. Conception and early pregnancy in the mare: lipidomics the unexplored frontier.. Reprod Fertil 2022 Jan 1;3(1):R1-R18.
- Rudolf Vegas A, Podico G, Canisso IF, Bollwein H, Almiñana C, Bauersachs S. Spatiotemporal endometrial transcriptome analysis revealed the luminal epithelium as key player during initial maternal recognition of pregnancy in the mare.. Sci Rep 2021 Nov 16;11(1):22293.
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