A specific adenylyl cyclase inhibitor (DDA) and a cyclic AMP-dependent protein kinase inhibitor (H-89) block the action of equine growth hormone on in vitro maturation of equine oocytes.
Abstract: The objectives of this study were firstly to determine whether the stimulatory function of equine growth hormone (eGH) on equine oocyte maturation in vitro is mediated via cyclic adenosine monophosphate (cAMP); and secondly if the addition of eGH in vitro influences oocyte nuclear maturation and if this effect is removed when GH inhibitors are added to the culture. Cumulus-oocyte complexes (COCs) were recovered from follicles <25 mm in diameter and randomly allocated as follows: (i) control (no additives); and (ii) 400 ng/ml of eGH. A specific inhibitor against cyclic AMP-dependent protein kinase (H-89; 10-9, 10-11 or 10-15 M concentration) and a specific adenylate cyclase inhibitor, 2',3'-dideoxyadenosine (DDA; 10-8, 10-10 or 10-14 M concentration) were used to observe whether they could block the eGH effect. After 30 h of in vitro maturation at 38.5°C with 5% CO2 in air, oocytes were stained with 10 μg/ml of Hoechst to evaluate nuclear status. More mature oocytes (P < 0.05) were detected when COCs were incubated with eGH (29 of 84; 34.5%) than in the control group (18 of 82; 21.9%). The H-89 inhibitor used at a concentration of 10-9 M (4 of 29; 13.8%) decreased (P < 0.05) the number of oocytes reaching nuclear maturation when compared with eGH (11 of 29; 38%). The DDA inhibitor at a concentration of 10-8 M (2 of 27; 7.4%) also reduced (P < 0.05) the number of oocytes reaching maturity when compared with the eGH group (9 of 30; 30%). Results from the present study show that H-89 and DDA can be used in vitro to block the eGH effect on equine oocyte maturation.
Publication Date: 2014-09-26 PubMed ID: 25257826DOI: 10.1017/S0967199414000434Google Scholar: Lookup
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- Journal Article
- Research Support
- Non-U.S. Gov't
Summary
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The research study investigates the role of equine growth hormone in the in vitro maturation of horse eggs, and how specific inhibitors can impact the process. The findings conclude that the growth hormone does affect egg maturation, and its impacts can be blocked by certain inhibitors.
Study Objectives and Set Up
- The study primarily aimed to investigate if the stimulatory effect of equine Growth Hormone (eGH) on equine oocyte (horse egg) maturation in the lab was mediated through a molecular messenger called cyclic adenosine monophosphate (cAMP).
- The secondary objective was to find out if additional eGH in the lab influenced oocyte nuclear maturation, and whether this effect could be negated with Growth Hormone inhibitors.
Methodology
- Cumulus-Oocyte Complexes (COCs) were obtained from follicles smaller than 25mm in diameter. These complexes were randomly assigned either to a control group (no additives) or a group treated with eGH.
- To examine if the effect of eGH can be blocked, two inhibitors were employed: H-89, a cyclic AMP-dependent protein kinase inhibitor and 2′,3′-dideoxyadenosine (DDA), a specific adenylate cyclase inhibitor.
- The COCs were cultured for 30 hours at 38.5°C with 5% CO2 in air, after which they were stained with a Hoechst dye to assess the status of the nucleus.
Results and Conclusion
- COCs treated with eGH yielded a significantly higher proportion of mature oocytes compared to the control group, indicating that eGH does stimulate in vitro oocyte maturation.
- This effect, however, was diminished when the COCs were treated with either H-89 or DDA. The number of oocytes that reached maturity was significantly reduced when the inhibitors were used at certain concentrations, as compared to the eGH group.
- This finding confirms that the stimulatory effect of eGH can be blocked and suggests that eGH’s effect on oocyte maturation is mediated through a cAMP-dependent pathway.
Cite This Article
APA
Pereira GR, Lorenzo PL, Carneiro GF, Bilodeau-Goeseels S, Kastelic J, Liu IK.
(2014).
A specific adenylyl cyclase inhibitor (DDA) and a cyclic AMP-dependent protein kinase inhibitor (H-89) block the action of equine growth hormone on in vitro maturation of equine oocytes.
Zygote, 23(6), 795-801.
https://doi.org/10.1017/S0967199414000434 Publication
Researcher Affiliations
- Animal Science Department,School of Agronomy,Federal University of Rio Grande do Sul,Campus Agronomia,Ave. Bento Gonçalves 7712,Porto Alegre,91540-000,RS,Brasil.
- Animal Physiology Department,Veterinary School,Universidad Complutense de Madrid,Madrid,Spain.
- Animal Reproduction Department,Garanhuns Academic Unity,Federal Rural University of Pernambuco,Garanhuns,PE,Brazil.
- Agriculture and Agri-Food Canada Research Centre,Lethbridge,Canada.
- Agriculture and Agri-Food Canada Research Centre,Lethbridge,Canada.
- Department of Population Health and Reproduction,School of Veterinary Medicine,University of California,Davis,CA,USA.
MeSH Terms
- Adenylyl Cyclase Inhibitors / pharmacology
- Animals
- Cyclic AMP-Dependent Protein Kinases / antagonists & inhibitors
- Dideoxyadenosine / pharmacology
- Female
- Growth Hormone / pharmacology
- Horses
- In Vitro Oocyte Maturation Techniques / methods
- Isoquinolines / pharmacology
- Oocytes / drug effects
- Oocytes / physiology
- Protein Kinase Inhibitors / pharmacology
- Sulfonamides / pharmacology
Citations
This article has been cited 2 times.- Li Y, Liu H, Yu Q, Liu H, Huang T, Zhao S, Ma J, Zhao H. Growth Hormone Promotes in vitro Maturation of Human Oocytes. Front Endocrinol (Lausanne) 2019;10:485.
- Hull KL, Harvey S. Growth hormone and reproduction: a review of endocrine and autocrine/paracrine interactions. Int J Endocrinol 2014;2014:234014.
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