Luteal luteinizing hormone receptors during the postovulatory period in the mare.
Abstract: Changes in serum luteinizing hormone (LH) and progesterone concentrations, number of luteal unoccupied LH receptors, receptor affinity constants, luteal weights and luteal progesterone concentrations were determined during the postovulatory period in the mare. The number of unoccupied LH receptors and receptor affinity was less during the early (Days 1-4) and late [Day 15 through 3rd day after start of corpus luteum (CL) regression] luteal phases than during the mid-luteal (Days 9-14) phase of the postovulatory period (P less than 0.01). The number of LH receptors per CL increased 21-fold (P less than 0.001) from Day 1 to Day 14. Receptor affinity increased 5-fold (P less than 0.001) from Day 1 to Day 13. Receptor number was highly correlated with receptor affinity (P less than 0.01) and both were highly correlated with serum and luteal progesterone (P less than 0.01). During regression of the CL, the number of LH receptors and receptor affinity decreased concomitantly with serum and luteal progesterone. Morphologically, luteal cell development and degeneration correlated with the change in receptor numbers, affinity constants and luteal and serum progesterone concentrations. Receptor number and affinity, luteal weight and serum and luteal progesterone concentrations did not differ between the CL from multiple ovulations. Random variations in the data observed between CL from multiple and single ovulations suggested that CL from the two groups were not different in structure and function. In summary, the above results suggest that major factors in regulation of progesterone secretion and maintenance of the equine CL are changes in the number of LH receptors and the affinity constants throughout the postovulatory period.
Publication Date: 1983-09-01 PubMed ID: 6315095DOI: 10.1095/biolreprod29.2.499Google Scholar: Lookup
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- Journal Article
Summary
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The study explores the changes in several hormone levels, receptor numbers, and receptor affinity throughout the postovulatory period in mares. The results indicate that the number of luteinizing hormone (LH) receptors and their affinity to connect with these hormones play a significant role in regulating progesterone secretion and maintaining the corpus luteum, a temporary hormone-secreting structure in mares.
Research Methods and Measurement
- The research analyses the changes in serum luteinizing hormone (LH) and progesterone concentrations during the postovulatory period in mares.
- Other factors like the number of unoccupied luteal LH receptors, receptor affinity constants, luteal weights, and luteal progesterone concentrations were also taken into account.
Results and Findings
- The study found that the number of unoccupied LH receptors and their affinity were less during the early and late luteal phases than during the mid-luteal phase of the postovulatory period.
- The number of LH receptors per corpus luteum increased dramatically from Day 1 to Day 14.
- Similarly, receptor affinity also saw a significant increase from Day 1 to Day 13.
- There was a high correlation between receptor number and affinity, and they were both highly correlated with serum and luteal progesterone.
Research Conclusions
- The research concluded that during the regression of the corpus luteum, the number of LH receptors and receptor affinity decreased alongside serum and luteal progesterone.
- Morphological factors, such as luteal cell development and degeneration, were linked with changes in receptor numbers, affinity constants, and luteal and serum progesterone concentrations.
- The study found that receptor number and affinity, luteal weight, and serum and luteal progesterone concentrations did not differ between the corpus luteum from multiple ovulations.
- The researchers noted that any variations observed between the corpus luteum from multiple and single ovulations seemed to be random, indicating that there was no significant difference in their structure and function.
- Ultimately, these results suggest that the major factors in regulating progesterone secretion and maintaining the equine corpus luteum are the changes in the number of LH receptors and the affinity constants throughout the postovulatory period.
Cite This Article
APA
Roser JF, Evans JW.
(1983).
Luteal luteinizing hormone receptors during the postovulatory period in the mare.
Biol Reprod, 29(2), 499-510.
https://doi.org/10.1095/biolreprod29.2.499 Publication
Researcher Affiliations
MeSH Terms
- Animals
- Corpus Luteum / analysis
- Corpus Luteum / physiology
- Estrus
- Female
- Horses / physiology
- Ovulation
- Pregnancy
- Progesterone / analysis
- Progesterone / physiology
- Receptors, Cell Surface / analysis
- Receptors, Cell Surface / physiology
- Receptors, LH
Citations
This article has been cited 3 times.- Piotrowska-Tomala KK, Jonczyk AW, Szóstek-Mioduchowska AZ, Żebrowska E, Ferreira-Dias G, Skarzynski DJ. The Effects of Prostaglandin E(2) Treatment on the Secretory Function of Mare Corpus Luteum Depends on the Site of Application: An in vivo Study.. Front Vet Sci 2021;8:753796.
- Kowalewski MP, Michel E, Gram A, Boos A, Guscetti F, Hoffmann B, Aslan S, Reichler I. Luteal and placental function in the bitch: spatio-temporal changes in prolactin receptor (PRLr) expression at dioestrus, pregnancy and normal and induced parturition.. Reprod Biol Endocrinol 2011 Aug 3;9:109.
- de Mestre AM, Hanlon D, Adams AP, Runcan E, Leadbeater JC, Erb HN, Costa CC, Miller D, Allen WR, Antczak DF. Functions of ectopically transplanted invasive horse trophoblast.. Reproduction 2011 Jun;141(6):849-56.
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