Expression of inhibins, activins, insulin-like growth factor-I and steroidogenic enzymes in the equine placenta.
Abstract: In this study, the expression patterns of inhibins, activins, insulin-like growth factor-I (IGF-I) and steroidogenic enzymes in equine placentae recovered during the latter two-thirds of gestation were examined. Concentrations of inhibin A and inhibin pro-alphaC in endometrial and fetal placental tissue homogenates were very low during the period examined, whereas these tissues contained high concentrations of activin A. In both maternal endometrial and fetal placental tissues, activin A levels decreased as pregnancy progressed. Expression of inhibin alpha-subunit was not observed in the placenta using either immunohistochemistry or in situ hybridization. Inhibin/activin betaA-subunit and its mRNA were confined to maternal endometrial glands, whereas immunopositive betaB-subunit was not detected in either endometrial glands or microcotyledons. Cytochrome P450 side chain cleavage enzyme was detected by immunohistochemistry in both endometrial glands and microcotyledons, whereas cytochrome P450 17alpha-hydroxylase/lyase was absent in these tissues. Immunopositive signals for 3beta-hydroxysteroid dehydrogenase and cytochrome P450 aromatase were localized in microcotyledons but not in endometrial glands. Immunohistochemistry revealed that IGF-I was highly expressed in microcotyledons around Day 130, and decreased as pregnancy progressed. Changes in the expression of IGF-I were correlated with the number of PCNA positive cells in the placenta. The present study demonstrated the presence and localized the site of expression of activin, IGF-I and steroidogenic enzymes in equine placental tissues during the latter two-thirds of gestation; the results suggest that activin and IGF-I may be involved in the regulation of placental development.
Publication Date: 2005-09-29 PubMed ID: 16233970DOI: 10.1016/j.domaniend.2005.09.005Google Scholar: Lookup
The Equine Research Bank provides access to a large database of publicly available scientific literature. Inclusion in the Research Bank does not imply endorsement of study methods or findings by Mad Barn.
- Journal Article
- Research Support
- Non-U.S. Gov't
Summary
This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.
The study explores the expressions of various hormones and enzymes – inhibins, activins, insulin-like growth factor-I (IGF-I) and steroidogenic enzymes – in the placenta of horses during the last two-thirds of the gestation period. It suggests that the hormones activin and IGF-I could play a role in the regulation of placental development.
Key Findings
- The study found that the endometrial and fetal placental tissue contained low concentrations of inhibin A and inhibin pro-alphaC throughout the examined gestation period, but high concentrations of activin A.
- Levels of activin A in both the maternal endometrial and fetal placental tissues were found to decrease as pregnancy progressed.
- The expression of inhibin alpha-subunit was not observed in the placenta. However, the inhibin/activin betaA-subunit and its mRNA were confined to maternal endometrial glands and were absent in both endometrial glands and microcotyledons.
- The research revealed that cytochrome P450 side chain cleavage enzyme was detected in both endometrial glands and microcotyledons, whereas cytochrome P450 17alpha-hydroxylase/lyase was absent in these tissues.
- Immunopositive signals for 3beta-hydroxysteroid dehydrogenase and cytochrome P450 aromatase were located in microcotyledons but not in endometrial glands.
Insulin-like growth factor-I (IGF-I)
- IGF-I was found to be highly expressed in microcotyledons around Day 130 and decreased as pregnancy progressed.
- The study also found that changes in the expression of IGF-I correlated with the number of PCNA positive cells in the placenta. This suggests that IGF-I may have an important role in placental development.
Conclusion
- This study contributed to the understanding of the role of various hormones and enzymes in equine placental tissues during gestation.
- The results suggest that activin and IGF-I may be involved in the regulation of placental development, offering insight for future research into placental development and potential complications in equine pregnancies.
Cite This Article
APA
Arai KY, Tanaka Y, Taniyama H, Tsunoda N, Nambo Y, Nagamine N, Watanabe G, Taya K.
(2005).
Expression of inhibins, activins, insulin-like growth factor-I and steroidogenic enzymes in the equine placenta.
Domest Anim Endocrinol, 31(1), 19-34.
https://doi.org/10.1016/j.domaniend.2005.09.005 Publication
Researcher Affiliations
- Department of Tissue Physiology, Tokyo University of Agriculture and Technology, Tokyo 183-8509, Japan.
MeSH Terms
- 3-Hydroxysteroid Dehydrogenases / biosynthesis
- Activins / biosynthesis
- Activins / genetics
- Animals
- Aromatase / biosynthesis
- Endometrium / metabolism
- Female
- Horses / metabolism
- Immunohistochemistry
- In Situ Hybridization
- Inhibin-beta Subunits / biosynthesis
- Inhibin-beta Subunits / genetics
- Inhibins / biosynthesis
- Inhibins / genetics
- Inhibins / physiology
- Insulin-Like Growth Factor I / biosynthesis
- Male
- Placenta / enzymology
- Placenta / metabolism
- Pregnancy
- Proliferating Cell Nuclear Antigen / biosynthesis
- RNA, Messenger / biosynthesis
- RNA, Messenger / genetics
Use Nutrition Calculator
Check if your horse's diet meets their nutrition requirements with our easy-to-use tool Check your horse's diet with our easy-to-use tool
Talk to a Nutritionist
Discuss your horse's feeding plan with our experts over a free phone consultation Discuss your horse's diet over a phone consultation
Submit Diet Evaluation
Get a customized feeding plan for your horse formulated by our equine nutritionists Get a custom feeding plan formulated by our nutritionists
