The efficacy of a single chain recombinant equine luteinizing hormone (reLH) in mares: induction of ovulation, hormone profiles, and inter-ovulatory intervals.
Abstract: The objectives of this study were to determine the efficacy of recombinant equine luteinizing hormone (reLH) in shortening the time to ovulation in cycling mares and to determine the effects of treatment on endogenous hormones and inter-ovulatory intervals. In study 1, mares of light horse breeds (3-20 years) were treated with either a vehicle, various doses of reLH, or human chorionic gonadotropin (hCG). Cycling mares were examined by palpation and ultrasound per rectum daily or every 12h from the time of treatment to ovulation. In studies 2 and 3, jugular blood samples were collected daily or every 12h from the time of treatment to ovulation for analysis of LH, follicle stimulating hormone (FSH), estradiol-17beta (E(2)), and progesterone (P(4)) by radioimmunoassays (RIA). Increasing doses of reLH (0.3, 0.6, 0.75, and 0.9 mg) showed increasing effectiveness at inducing ovulation within 48 h of treatment. Treatments with the 0.75 and 0.9 mg doses of reLH resulted in 90% and 80% ovulation rates, which were similar to hCG treatment (85.7%). Except for the early rise in LH after treatment with 0.5, 0.65, and 1.0mg of reLH, hormone profiles appeared to be similar between control and treated cycles. Inter-ovulatory intervals were similar between control and treatment cycles. In conclusion, reLH is a reliable and effective ovulatory agent that does not significantly alter endogenous hormone profiles or affect inter-ovulatory intervals.
Publication Date: 2007-06-28 PubMed ID: 17658237DOI: 10.1016/j.domaniend.2007.06.001Google Scholar: Lookup
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- Journal Article
- Research Support
- Non-U.S. Gov't
Summary
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The research article delves into the effectiveness of recombinant equine luteinizing hormone (reLH) in inducing ovulation in mares, its impact on hormone profiles, and inter-ovulatory intervals. Researchers found that reLH effectively induces ovulation within 48 hours of treatment in increasing dosages, and it does not significantly change hormone profiles or affect inter-ovulatory intervals.
Research Methods
- The results presented in this study are based on three different studies. In the first one, mares of ages between 3-20 years were treated with either a vehicle, various doses of reLH, or human chorionic gonadotropin (hCG). The condition of the mares was examined via palpation and ultrasound per rectum every 12 hours or daily from the time they received treatment until ovulation.
- The second and third studies involved collecting jugular blood samples from the time the mares were treated up to ovulation. This was done daily or every 12 hours for analysis of various hormones: Luteinizing hormone (LH), follicle-stimulating hormone (FSH), estradiol-17beta (E2), and progesterone (P4).
Results and Findings
- Performance of reLH in inducing ovulation was dose-dependent; increasing doses of reLH (0.3, 0.6, 0.75, and 0.9 mg) showed effectiveness in inducing ovulation within 48 hours of treatment, with the 0.75 and 0.9 mg doses achieving ovulation rates of 90% and 80% respectively. These results were comparable to those of hCG treatment which achieved 85.7% ovulation.
- In terms of hormone profiles, except for the early rise in LH after treatment with 0.5, 0.65, and 1.0mg of reLH, all hormone profiles were similar between the control and treated cycles. This suggests that reLH does not significantly alter endogenous hormone profiles.
- Inter-ovulatory intervals, the time period between two ovulation cycles, were found to be similar between both control and treatment cycles, indicating that reLH does not affect inter-ovulatory intervals.
Conclusion
- The research study concluded that reLH is a reliable and effective agent which can be used to induce ovulation in mares. It also indicated that reLH does not significantly alter endogenous hormone profiles or inter-ovulatory intervals, making it a safe agent for the purpose it is intended.
Cite This Article
APA
Yoon MJ, Boime I, Colgin M, Niswender KD, King SS, Alvarenga M, Jablonka-Shariff A, Pearl CA, Roser JF.
(2007).
The efficacy of a single chain recombinant equine luteinizing hormone (reLH) in mares: induction of ovulation, hormone profiles, and inter-ovulatory intervals.
Domest Anim Endocrinol, 33(4), 470-479.
https://doi.org/10.1016/j.domaniend.2007.06.001 Publication
Researcher Affiliations
- Department of Animal Science, University of California, Davis, CA 95616, USA.
MeSH Terms
- Animals
- Estradiol / blood
- Female
- Follicle Stimulating Hormone / blood
- Hormones / blood
- Horses / physiology
- Luteinizing Hormone / administration & dosage
- Luteinizing Hormone / blood
- Luteinizing Hormone / chemistry
- Ovulation
- Ovulation Induction / methods
- Ovulation Induction / veterinary
- Progesterone / blood
- Recombinant Proteins / administration & dosage
- Time Factors
Citations
This article has been cited 1 times.- Gifre L, Arís A, Bach À, Garcia-Fruitós E. Trends in recombinant protein use in animal production. Microb Cell Fact 2017 Mar 4;16(1):40.
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