Relationships between uterine blood flow, peripheral sex steroids, expression of endometrial estrogen receptors and nitric oxide synthases during the estrous cycle in mares.
Abstract: The objective of this study was to investigate the relationships between uterine perfusion and estrogen, progesterone and the uterine nitric oxide synthase (NOS) system in five trotter mares during the estrous cycle. Color Doppler sonography for measurement of uterine blood flow and collection of blood for determination of plasma estrogen and progesterone concentrations were performed on days 0 (= ovulation), 1, 5, 11 and 15 and daily during estrus (days -1 to -4) of one estrous cycle; endometrial biopsy collection for mRNA expression analysis of NOS and estrogen receptors was performed on days 0, 1, 5, 11, 15 and -3. Blood flow in each uterine artery was assessed by calculating the mean time-averaged maximum velocity (TAMV) and the pulsatility index (PI). Plasma concentrations of estrogen and progesterone were determined using specific enzyme immunoassays. The mRNA expressions of endothelial NOS (eNOS), inducible NOS (iNOS) as well as estrogen receptors α (ERα) and β (ERβ) were quantified using reverse transcriptase-polymerase chain reaction (RT-PCR) analysis. The TAMV and PI had a biphasic pattern during the estrous cycle (P<0.05), with maximum and minimum, respectively, values on days 5 and -4. Estrogen receptor mRNA concentrations increased significantly during days 15 (ERα) and -3 (ERβ). Transcript expression of eNOS, but not iNOS, had a biphasic pattern during the cycle (P<0.05) with maximum levels on days 5 and -3 and correlated positively with TAMV (r=0.81, P=0.05). We infer that the uterine NOS system, especially eNOS, plays an important role in the regulation of uterine blood flow during the estrous cycle in mares.
Publication Date: 2010-10-12 PubMed ID: 20953124DOI: 10.1262/jrd.10-023tGoogle Scholar: Lookup
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- Journal Article
Summary
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The research article focuses on the study of how uterine blood flow, hormones like estrogen and progesterone, and the production of nitric oxide interrelate in mares (female horses) during their estrous cycle (reproductive cycle). The study suggests that the nitric oxide system in the uterus, particularly endothelial nitric oxide synthase (eNOS), significantly influences uterine blood flow through the cycle.
Objectives and Methods of the Study
- The principal aim of the research was to understand the linkage between uterine blood flow, estrogen, progesterone, and the uterine nitric oxide synthase (NOS) system in mares during the estrous cycle.
- Five trotter mares were monitored during one estrous cycle. The research process involved the use of color Doppler sonography to measure uterine blood flow, collection of blood samples for determining concentrations of estrogen and progesterone, and endometrial biopsy collection for mRNA expression analysis of NOS and estrogen receptors. This was performed at specific intervals during the estrous cycle.
- Indicators of blood flow in the uterine arteries, the Time-Averaged Maximum Velocity (TAMV), and the Pulsatility Index (PI) were assessed.
- Estrogen and progesterone levels were evaluated using enzyme immunoassays. mRNA levels of eNOS and inducible NOS (iNOS), as well as estrogen receptors α (ERα) and β (ERβ), were measured using Reverse Transcriptase-Polymerase Chain Reaction (RT-PCR).
Findings of the Study
- The TAMV and PI displayed a biphasic pattern (two phases) during the estrous cycle, reaching their highest and lowest values, respectively, on day 5 and day -4.
- Estrogen receptor mRNA concentrations increased significantly during day 15 (ERα) and day -3 (ERβ).
- The transcript expression of eNOS, but not iNOS, also displayed a clear biphasic pattern during the cycle, peaking on day 5 and day -3, suggesting that eNOS closely correlates with TAMV, and thus with uterine blood flow.
- Given these findings, the researchers concluded that the uterine NOS system, especially eNOS, plays a critical role in the regulation of uterine blood flow during the estrous cycle in mares.
Cite This Article
APA
Honnens A, Weisser S, Welter H, Einspanier R, Bollwein H.
(2010).
Relationships between uterine blood flow, peripheral sex steroids, expression of endometrial estrogen receptors and nitric oxide synthases during the estrous cycle in mares.
J Reprod Dev, 57(1), 43-48.
https://doi.org/10.1262/jrd.10-023t Publication
Researcher Affiliations
- Clinic for Cattle, School of Veterinary Medicine Hannover, 30173 Hannover, Germany. aenne.honnens@tiho-hannover.de
MeSH Terms
- Animals
- Biopsy / veterinary
- Blood Flow Velocity / veterinary
- Endometrium / cytology
- Endometrium / metabolism
- Estrogens / blood
- Estrous Cycle / blood
- Estrous Cycle / physiology
- Female
- Gene Expression Regulation
- Gonadal Steroid Hormones / blood
- Horses / physiology
- Nitric Oxide Synthase / genetics
- Nitric Oxide Synthase / metabolism
- Progesterone / blood
- Protein Isoforms / genetics
- Protein Isoforms / metabolism
- RNA, Messenger / metabolism
- Receptors, Estrogen / genetics
- Receptors, Estrogen / metabolism
- Regional Blood Flow
- Reverse Transcriptase Polymerase Chain Reaction / veterinary
- Ultrasonography, Doppler, Color / veterinary
- Uterine Artery / diagnostic imaging
- Uterus / blood supply
- Uterus / diagnostic imaging
Citations
This article has been cited 4 times.- Jasiński T, Zdrojkowski Ł, Ferreira-Dias G, Kautz E, Juszczuk-Kubiak E, Domino M. Molecular Mechanism of Equine Endometrosis: The NF-κB-Dependent Pathway Underlies the Ovarian Steroid Receptors' Dysfunction. Int J Mol Sci 2022 Jul 1;23(13).
- Yama P, Yadmak C, Sangkate M, Jitjumnong J, U-Krit W, Promsao N, Montha N, Sudwan P, Mektrirat R, Panatuk J, Inyawilert W, Sringarm K, Lumsangkul C, Tapingkae W, Doan HV, Tang PC, Moonmanee T. In Vivo Follicular and Uterine Arterial Indices as an Indicator of Successful Hormonal Stimulation for Inactive Ovaries in Repeat-Breeder Crossbred Dairy Cows Using a Short-Term Progesterone-Based Programme. Animals (Basel) 2022 Jan 25;12(3).
- Bai J, Qi QR, Li Y, Day R, Makhoul J, Magness RR, Chen DB. Estrogen Receptors and Estrogen-Induced Uterine Vasodilation in Pregnancy. Int J Mol Sci 2020 Jun 18;21(12).
- Vercellini R, Blanco PG, Arizmendi A, Diez M, Rodríguez R, Gobello C. Ovarian and uterine two-dimensional and Doppler ultrasonographic changes in the feline peri-estrus period. J Feline Med Surg 2022 Oct;24(10):1053-1059.
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