Effect of repeated administration of oxytocin during diestrus on duration of function of corpora lutea in mares.
Abstract: To determine whether IM administration of exogenous oxytocin twice daily on days 7 to 14 after ovulation blocks luteolysis and causes prolonged function of corpora lutea (CL) in mares. Methods: Prospective study. Methods: 12 mares. Methods: Beginning on the day of ovulation (day 0), jugular blood samples were collected every other day until day 40 for determination of progesterone concentration. On day 7, mares (n = 6/group) were treated with saline (0.9% NaCl) solution (control group) or oxytocin. Beginning on day 7, control mares received 3 mL of sterile saline solution every 12 hours, IM, and oxytocin-treated mares received 60 units of oxytocin every 12 hours, IM, through day 14. Mares were considered to have prolonged CL function if progesterone concentration remained > 1.0 ng/mL continuously through day 30. Results: The proportion of mares with prolonged CL function was significantly higher in the oxytocin-treated group (6/6), compared with the control group (0/6). All control mares underwent luteolysis by day 16, at which time their progesterone concentrations were < 1.0 ng/mL. In contrast, all 6 oxytocin-treated mares maintained progesterone concentrations > 1.0 ng/mL continuously through day 30. Conclusions: IM administration of 60 units of oxytocin twice daily on days 7 to 14 after ovulation was an efficacious method of inhibiting luteolysis and extending CL function in mares. Disrupting luteolysis by administering exogenous oxytocin during diestrus appears to be a plausible and practical method of long-term suppression of estrus in mares.
Publication Date: 2007-12-18 PubMed ID: 18081527DOI: 10.2460/javma.231.12.1864Google Scholar: Lookup
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- Journal Article
- Research Support
- Non-U.S. Gov't
Summary
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The research article deals with the impact of injecting oxytocin into mares twice a day from day 7 to day 14 post-ovulation to delay the regression of corpora lutea.
Study Purpose and Methodology
- The objective of the study was to assess whether intramuscular (IM) injections of exogenous oxytocin (twice daily) from day 7 to 14 following ovulation can inhibit the lysis (degradation) of the corpora lutea in mares, thus resulting in their prolonged function.
- The study was prospective, involving 12 mares divided equally into two groups. From the day of ovulation (day 0), blood samples were taken every alternate day until day 40 to measure progesterone levels, which acts as an indicator for the function of the corpora lutea.
- On the 7th day post-ovulation, the mares in the control group were given sterile saline solution injections (3 mL), while the other group received 60 units of oxytocin. These injections were given twice daily until the 14th day post-ovulation.
- The corpora lutea were considered to have a prolonged function if the progesterone level stayed above a certain threshold (more than 1.0 ng/mL) continuously till the 30th day.
Study Findings
- Results revealed a significantly higher number of mares in the oxytocin-treated group (6/6) who exhibited extended corpora lutea function in comparison to the control group (0/6).
- All mares from the control group experienced corpora lutea degradation by the 16th day, marked by progesterone levels dropping below 1.0 ng/mL. On the contrary, all oxytocin-treated mares preserved a progesterone concentration above 1.0 ng/mL continuously through the 30th day.
Conclusions
- The study concludes that intramuscular administration of 60 units of exogenous oxytocin twice daily from day 7 to 14 after ovulation is an effective method to inhibit the degradation process of the corpora lutea, thereby extending their function in mares.
- This innovative use of oxytocin injections during diestrus could potentially offer a feasible strategy for prolonged estrus suppression in mares.
Cite This Article
APA
Vanderwall DK, Rasmussen DM, Woods GL.
(2007).
Effect of repeated administration of oxytocin during diestrus on duration of function of corpora lutea in mares.
J Am Vet Med Assoc, 231(12), 1864-1867.
https://doi.org/10.2460/javma.231.12.1864 Publication
Researcher Affiliations
- Department of Animal and Veterinary Science, and the Center for Reproductive Biology, College of Agricultural and Life Sciences, University of Idaho, Moscow, ID 83844-2201, USA.
MeSH Terms
- Animals
- Area Under Curve
- Corpus Luteum / drug effects
- Corpus Luteum / physiology
- Diestrus / drug effects
- Diestrus / physiology
- Female
- Horses / blood
- Horses / physiology
- Injections, Intramuscular / veterinary
- Luteolysis / drug effects
- Luteolysis / physiology
- Ovulation
- Oxytocics / pharmacology
- Oxytocin / pharmacology
- Progesterone / blood
- Prospective Studies
Citations
This article has been cited 2 times.- Diel de Amorim M, Dong L, Byron M, Foster RA, Klein C, Saleh M, Saleh T, Card C. Characterization of serum and tissue oxytocinase and tissue oxytocin in the pregnant and non-pregnant mare.. Sci Rep 2023 Mar 21;13(1):4616.
- Diel de Amorim M, Klein C, Foster R, Dong L, Lopez-Rodriguez MF, Card C. Expression of Oxytocin/Neurophysin I and Oxytocinase in the Equine Conceptus from Day 8 to Day 21 Post-Ovulation.. Animals (Basel) 2022 Mar 22;12(7).
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