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Serum progesterone and oxytocinase, and endometrial and luteal gene expression in pregnant, nonpregnant, oxytocin, carbetocin and meclofenamic acid treated mares. Theriogenology 2023; 198:47-60. [PMID: 36549183 DOI: 10.1016/j.theriogenology.2022.10.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Revised: 10/14/2022] [Accepted: 10/15/2022] [Indexed: 12/24/2022]
Abstract
Our objectives were to examine changes in endometrial and luteal gene expression during estrus, diestrus, pregnancy and treatments to induce luteolysis and putatively induce luteostasis. Groups were: Diestrus (DIEST), Estrus (ESTR), Pregnant (PREG), Oxytocin (OXY), Carbetocin (CARB), and Meclofenamic acid (MFA). Blood was obtained from day (D)12 to D15 for measurement of oxytocinase, also referred to as leucyl-cysteinyl aminopeptidase (LNPEP) and progesterone. Luteal biopsies were obtained on D12 and D15 and an endometrial biopsy on D15. Real-time RT-PCR was performed for the following genes: PGR, ESR1, OXTR,OXT, LNPEP, PTGS2, PTGFR, PLA2G2C, PTGES, SLC2A4, and SLC2A1. Regarding serum LNPEP, PREG and OXY (p-value<0.001) had higher concentrations than DIEST mares. Endometrial PTGES expression was higher (p-value <0.04) in DIEST, PREG and OXY than other groups. Endometrium from ESTR had increased expression of OXT (p-value < 0.02) compared to MFA and OXY mares. Carbetocin treatment: decreased serum progesterone and LNPEP; increased endometrial PLA2G2C; decreased endometrial PTGES; and decreased luteal aromatase and PTGES. Treatment with MFA: decreased endometrial PLA2G2C, increased endometrial PTGES; and resulted in less OXTR and OXT luteal abundance on D12 compared to D15. Endometrial and luteal expression of LNPEP is affected by physiologic stage and treatment and is involved in luteal function and pregnancy recognition pathways through effects on oxytocin and prostaglandin synthesis in the horse.
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Domingues RR, Ginther OJ, Gomez-Leon V, Castro T, Wiltbank MC. Endometrial and luteal responses to a prostaglandin F2alpha pulse: A comparison between heifers and mares. Biol Reprod 2022; 106:979-991. [DOI: 10.1093/biolre/ioac025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Revised: 12/28/2021] [Accepted: 01/25/2022] [Indexed: 11/13/2022] Open
Abstract
Abstract
In heifers and mares, multiple pulses of prostaglandin F2alpha (PGF) are generally associated with complete luteal regression. Although PGF pulses occur before and during luteolysis, little is known about the role of minor PGF pulses during preluteolysis on subsequent luteal and endometrial PGF production that may initiate luteolysis. Heifers (n = 7/group) and mares (n = 6/group) were treated with a single minor dose of PGF (3.0 and 0.5 mg, respectively) during mid-luteal phase (12 and 10 days postovulation in heifers and mares, respectively). After treatment, a transient decrease in progesterone (P4) concentrations occurred in heifers between Hours 0–2 but at Hour 4 P4 was not different from pre-treatment. In mares, P4 was unaltered between Hours 0 and 4. Concentrations of P4 decreased in both species by Hour 24 and complete luteolysis occurred in mares by Hour 48. Luteal and endometrial gene expression were evaluated 4 hours post-treatment. In heifers, luteal mRNA abundance of PGF receptor and PGF dehydrogenase were decreased while PTGS2, PGF transporter, and oxytocin receptor were increased. In the heifer endometrium, receptors for oxytocin, P4, and estradiol were upregulated. In mares, luteal expression of PGF receptor was decreased while PGF transporter and oxytocin receptor were increased. The decrease in P4 between Hours 4 and 24 and changes in gene expression were consistent with upregulation of endogenous synthesis of PGF. The hypotheses were supported that a single minor PGF treatment upregulates endogenous machinery for PGF synthesis in heifers and mares stimulating endogenous PGF synthesis through distinct regulatory mechanisms in heifers and mares.
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Affiliation(s)
- Rafael R Domingues
- Department of Animal and Dairy Sciences, University of Wisconsin-Madison, Madison, WI, USA
- Endocrinology and Reproductive Physiology Program, University of Wisconsin-Madison, Madison, WI, USA
- Eutheria Foundation, Cross Plains, WI, USA
| | - O J Ginther
- Eutheria Foundation, Cross Plains, WI, USA
- Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, WI, USA
| | - Victor Gomez-Leon
- Department of Animal and Dairy Sciences, University of Wisconsin-Madison, Madison, WI, USA
- Eutheria Foundation, Cross Plains, WI, USA
| | - Thadeu Castro
- Eutheria Foundation, Cross Plains, WI, USA
- Department of Veterinary Medicine, Universidade Federal Rural do Rio de Janeiro, Seropédica, RJ, Brazil
| | - Milo C Wiltbank
- Department of Animal and Dairy Sciences, University of Wisconsin-Madison, Madison, WI, USA
- Endocrinology and Reproductive Physiology Program, University of Wisconsin-Madison, Madison, WI, USA
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Ginther OJ, Domingues RR, Kennedy VC, Dangudubiyyam SV. Endogenous and exogenous effects of PGF2α during luteolysis in mares. Theriogenology 2019; 132:45-52. [PMID: 30991168 DOI: 10.1016/j.theriogenology.2019.04.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Revised: 04/02/2019] [Accepted: 04/04/2019] [Indexed: 12/14/2022]
Abstract
An inhibitor of PGF2α biosynthesis (flunixin meglumine, FM) was used to study the role of endogenous PGF2α on the luteolytic effect of exogenous PGF2α in mares. A 2-h infusion of PGF2α at a constant rate (total dose, 0.1 mg) on Day 10 (ovulation = Day 0) was used to mimic the maximal concentrations of a spontaneous pulse of a PGF2α metabolite (PGFM). Treatment with FM (1.7 mg/kg) was done 1 h before and 5 h after the start of PGF2α infusion. In hourly blood samples beginning 1 h before the start of PGF2α infusion, progesterone decreased (P < 0.05) similarly by 5 h in each of the PGF2α and PGF2α+FM groups but not in the controls (n = 5). In a study of spontaneous luteolysis, the same FM dose was given every 6 h from Day 13 until Day 17 or earlier if CL regression was indicated by an 80% decrease in luteal blood-flow signals. Blood was sampled for progesterone assay each day and 8 h of hourly blood sampling was done each day to characterize PGFM concentrations and pulses. Progesterone (P4) was lower (P < 0.05) in controls than in an FM group (n = 7) by Day 15. Luteolysis (P4 < 1 ng/mL) ended on Days 14-19 in individual controls. In contrast, luteolysis did not end until after Day 20 in 4 of 7 FM-treated mares. In the three mares with completion of luteolysis before Day 20 in the FM group, the interval from beginning to end of luteolysis was longer (P < 0.02) (4.5 ± 0.6 days) than in the controls (3.0 ± 0.4 days). During 8-h sessions of hourly blood sampling on Day 14, concentration of PGFM was significantly lower in the FM group for the minimal, mean, and maximal per session. Pulses of PGFM were identified by a CV methodology on each day in 7 of 7 and 3 of 7 mares in the controls and FM group, respectively. The four FM-treated mares without a CV-identified pulse were the four mares in which luteolysis did not occur before Day 20. In mares with detected pulses, PGFM was lower at each nadir and at the peak (86% lower) in the FM group than in controls, but the interval between nadirs or base of a pulse was not different between groups. Hypothesis 1 that endogenous PGF plays a role in the luteolytic effect of exogenous PGF2α was not supported. Hypothesis 2 that an inhibitor of PGF2α biosynthesis prevented or minimized the prominence of PGFM pulses and increased the frequency of persistent CL was supported.
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Affiliation(s)
- O J Ginther
- Eutheria Foundation, Cross Plains, WI, 53528, USA; Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, WI, 53706, USA.
| | - R R Domingues
- Eutheria Foundation, Cross Plains, WI, 53528, USA; Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - V C Kennedy
- Eutheria Foundation, Cross Plains, WI, 53528, USA
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TGFB1 modulates in vitro secretory activity and viability of equine luteal cells. Cytokine 2018; 110:316-327. [DOI: 10.1016/j.cyto.2018.03.038] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Revised: 03/21/2018] [Accepted: 03/28/2018] [Indexed: 01/02/2023]
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Ishak GM, Bashir ST, Dutra GA, Gastal GDA, Gastal MO, Cavinder CA, Feugang JM, Gastal EL. In vivo antral follicle wall biopsy: a new research technique to study ovarian function at the cellular and molecular levels. Reprod Biol Endocrinol 2018; 16:71. [PMID: 30055625 PMCID: PMC6064614 DOI: 10.1186/s12958-018-0380-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/20/2018] [Accepted: 06/26/2018] [Indexed: 01/09/2023] Open
Abstract
BACKGROUND In vivo studies involving molecular markers of the follicle wall associated with follicular fluid (FF) milieu are crucial for a better understanding of follicle dynamics. The inability to obtain in vivo samples of antral follicle wall (granulosa and theca cells) without jeopardizing ovarian function has restricted advancement in knowledge of folliculogenesis in several species. The purpose of this study in mares was to develop and validate a novel, minimally invasive in vivo technique for simultaneous collection of follicle wall biopsy (FWB) and FF samples, and repeated collection from the same individual, during different stages of antral follicle development. We hypothesized that the in vivo FWB technique provides samples that maintain the normal histological tissue structure of the follicle wall layers, offers sufficient material for various cellular and molecular techniques, and allows simultaneous retrieval of FF. METHODS In Experiment 1 (ex vivo), each follicle was sampled using two techniques: biopsy forceps and scalpel blade (control). In Experiment 2 (in vivo), FWB and FF samples from 10-, 20-, and 30-mm follicles were repeatedly and simultaneously obtained through transvaginal ultrasound-guided technique. RESULTS In Experiment 1, the thickness of granulosa, theca interna, and theca externa layers was not influenced (P > 0.05) by the harvesting techniques. In Experiment 2, the overall recovery rates of FWB and FF samples were 97 and 100%, respectively. However, the success rate of obtaining samples with all layers of the follicle wall and clear FF varied according to follicle size. The expression of luteinizing hormone receptor (LHR) was mostly confined in the theca interna layer, with the estradiol-related receptor alpha (ERRα) in the granulosa and theca interna layers. The 30-mm follicle group had greater (P < 0.05) LHR expression in the theca interna and ERRα in the granulosa layer compared to the other groups. The overall expression of LHR and ERRα, and the intrafollicular estradiol were higher (P < 0.05 - P < 0.0001) in the 30-mm follicle group. CONCLUSION The in vivo technique developed in this study can be repeatedly and simultaneously used to provide sufficient FWB and FF samples for various cellular and molecular studies without jeopardizing the ovarian function, and has the potential to be translated to other species, including humans.
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Affiliation(s)
- G M Ishak
- Department of Animal Science, Food and Nutrition, Southern Illinois University, 1205 Lincoln Drive, MC 4417, Carbondale, IL, 62901, USA
- Department of Surgery and Obstetrics, College of Veterinary Medicine, University of Baghdad, Baghdad, Iraq
| | - S T Bashir
- Department of Animal Science, Food and Nutrition, Southern Illinois University, 1205 Lincoln Drive, MC 4417, Carbondale, IL, 62901, USA
| | - G A Dutra
- Department of Animal Science, Food and Nutrition, Southern Illinois University, 1205 Lincoln Drive, MC 4417, Carbondale, IL, 62901, USA
| | - G D A Gastal
- Department of Animal Science, Food and Nutrition, Southern Illinois University, 1205 Lincoln Drive, MC 4417, Carbondale, IL, 62901, USA
| | - M O Gastal
- Department of Animal Science, Food and Nutrition, Southern Illinois University, 1205 Lincoln Drive, MC 4417, Carbondale, IL, 62901, USA
| | - C A Cavinder
- Department of Animal and Dairy Sciences, Mississippi State University, Mississippi State, MS, USA
| | - J M Feugang
- Department of Animal and Dairy Sciences, Mississippi State University, Mississippi State, MS, USA
| | - E L Gastal
- Department of Animal Science, Food and Nutrition, Southern Illinois University, 1205 Lincoln Drive, MC 4417, Carbondale, IL, 62901, USA.
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Galvão AM, Skarzynski D, Ferreira-Dias G. Luteolysis and the Auto-, Paracrine Role of Cytokines From Tumor Necrosis Factor α and Transforming Growth Factor β Superfamilies. VITAMINS AND HORMONES 2018; 107:287-315. [PMID: 29544635 DOI: 10.1016/bs.vh.2018.01.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Successful pregnancy establishment demands optimal luteal function in mammals. Nonetheless, regression of the corpus luteum (CL) is absolutely necessary for normal female cyclicity. This dichotomy relies on intricate molecular signals and rapidly activated biological responses, such as angiogenesis, extracellular matrix (ECM) remodeling, or programmed cell death. The CL establishment and growth after ovulation depend not only on the luteinizing hormone-mediated endocrine signal but also on a number of auto-, paracrine interactions promoted by cytokines and growth factors like fibroblast growth factor 2, vascular endothelial growth factor A, and tumor necrosis factor α (TNF), which coordinate vascularigenesis and ECM reorganization as well as steroidogenesis. With the organ fully developed, the release of the uterine prostaglandin F2α activates luteolysis, an intricate process supported by intraluteal interactions that ensure the loss of steroidogenic function (functional luteolysis) and the involution of the organ (structural luteolysis). This chapter provides an overview of the local action of cytokines during luteal function, with particular emphasis on the role of TNF and transforming growth factor β superfamilies during luteolysis.
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Affiliation(s)
- António M Galvão
- C.I.I.S.A., Faculty of Veterinary Medicine, University of Lisbon, Lisbon, Portugal; Institute of Animal Reproduction and Food Research of PAS, Olsztyn, Poland.
| | - Dariusz Skarzynski
- Institute of Animal Reproduction and Food Research of PAS, Olsztyn, Poland
| | - Graça Ferreira-Dias
- C.I.I.S.A., Faculty of Veterinary Medicine, University of Lisbon, Lisbon, Portugal
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Brandão FAS, Alves BG, Alves KA, Souza SS, Silva YP, Freitas VJF, Teixeira DIA, Gastal EL. Laparoscopic ovarian biopsy pick-up method for goats. Theriogenology 2017; 107:219-225. [PMID: 29179058 DOI: 10.1016/j.theriogenology.2017.10.042] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2017] [Revised: 10/23/2017] [Accepted: 10/30/2017] [Indexed: 11/25/2022]
Abstract
Biopsy pick-up (BPU) has been considered a safe method to harvest ovarian fragments from live animals. However, no studies have been reported on the use of BPU to collect in vivo ovarian tissue in goats. The goals of this study were: (i) to test different biopsy needle sizes to collect ovarian tissue in situ using the BPU method (Experiment 1), and (ii) to study ovarian tissue features such as preantral follicle density, morphology, class distribution, and stromal cell density in ovarian fragments obtained in vivo through a laparoscopic BPU method (Experiment 2). In Experiment 1, goat ovaries (n = 20) were collected in a slaughterhouse and subjected to in situ BPU. Three needles (16, 18, and 20G) were tested. In Experiment 2, the most efficient biopsy needle from Experiment 1 was used to perform laparoscopic BPU in goats (n = 8). In Experiment 1, the recovery rate was greater (P < 0.05; range 50-62%) with 16G and 18G needles than the 20G (17%) needle. The mean weight of ovarian fragments collected by the 16G needle was greater (P < 0.05) than the 18G and the 20G needle. In Experiment 2, 62 biopsy attempts were performed and 52 ovarian fragments were collected (90% success rate). Overall, 2054 preantral follicles were recorded in 5882 histological sections analyzed. Mean preantral follicular density was 28.4 ± 1.3 follicles per cm2. The follicular density differed (P < 0.05) among animals and ovarian fragments within the same animal. The mean stromal cell density in the ovarian fragments was 37.1 ± 0.5 cells per 2500 μm2, and differed (P < 0.05) among animals. Moreover, preantral follicle density and stromal cell density were associated (P < 0.001). The percentage of morphologically normal follicles was 70.1 ± 1.2, and differed (P < 0.05) among animals. The majority (79%) of the morphologically normal follicles was classified as primordial follicles, and differed (P < 0.05) among animals and between ovaries. In summary, a laparoscopic BPU method has been developed to harvest ovarian tissue in vivo with a satisfactory success rate in goats. Furthermore, this study described for the first time that goat ovarian biopsy fragments have a high heterogeneity in follicular density, morphology, class distribution, and stromal cell density.
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Affiliation(s)
- Fabiana A S Brandão
- Laboratory of Physiology and Control of Reproduction, State University of Ceará, Fortaleza, CE, Brazil
| | - Benner G Alves
- Laboratory of Manipulation of Oocytes and Preantral Follicles, State University of Ceará, Fortaleza, CE, Brazil
| | - Kele A Alves
- Laboratory of Manipulation of Oocytes and Preantral Follicles, State University of Ceará, Fortaleza, CE, Brazil
| | - Samara S Souza
- Laboratory of Physiology and Control of Reproduction, State University of Ceará, Fortaleza, CE, Brazil
| | - Yago P Silva
- Laboratory of Physiology and Control of Reproduction, State University of Ceará, Fortaleza, CE, Brazil
| | - Vicente J F Freitas
- Laboratory of Physiology and Control of Reproduction, State University of Ceará, Fortaleza, CE, Brazil
| | - Dárcio I A Teixeira
- Laboratory of Physiology and Control of Reproduction, State University of Ceará, Fortaleza, CE, Brazil
| | - Eduardo L Gastal
- Department of Animal Science, Food and Nutrition, Southern Illinois University, Carbondale, IL, USA.
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9
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Ginther OJ. Systemic and intrafollicular components of follicle selection in mares. Domest Anim Endocrinol 2017; 59:116-133. [PMID: 28113119 DOI: 10.1016/j.domaniend.2016.12.005] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/20/2016] [Revised: 12/06/2016] [Accepted: 12/10/2016] [Indexed: 12/29/2022]
Abstract
Mares are superb models for study of follicle selection owing to similarities between mares and women in relative follicle diameters at specific events during the follicular wave and follicle accessibility for experimental sampling and manipulation. Usually, only 1 major follicular wave with a dominant follicle (DF) greater than 30 mm develops during the 22 to 24 d of the equine estrous cycle and is termed the primary or ovulatory wave. A major secondary wave occasionally (25%) develops early in the cycle. Follicles of the primary wave emerge at 6 mm on day 10 or 11 (day 0 = ovulation). The 2 largest follicles begin to deviate in diameter on day 16 when the future DF and largest subordinate follicle (SF) are 23 mm and 20 mm, respectively. The deviation process begins the day before diameter deviation as indicated in the future DF but not in the future SF by (1) increase in prominence of an anechoic layer and vascular perfusion of the wall and (2) increase in follicular-fluid concentrations of IGF1, vascular endothelial growth factor, estradiol, and inhibin-A. A systemic component of the deviation process is represented by suppression of circulating FSH from secretion of inhibin and estradiol from the developing DF. Production of inhibin is stimulated by IGF1 and LH, and estradiol is stimulated by LH and not by IGF1 in mares. A local intrafollicular component involves the production of IGF1, which apparently increases the responsiveness of the future DF to FSH. The roles of the IGF system have been well studied in mares, but the effect of IGF1 on increasing the sensitivity of the follicle cells to FSH is based primarily on studies in other species. The greater response of the future DF than the SF to the low concentrations of FSH is the essence of selection. During the common growth phase that precedes deviation, diameter of the 2 largest follicles increases in parallel on average when normalized to emergence or retrospectively to deviation. Study of individual waves indicates that (1) the 2 follicles change ranks (relative diameters) during the common growth phase in about 30% of primary waves and (2) after ablation of 1, 2, or 3 of the largest follicles at the expected beginning of deviation, the next largest retained follicle becomes the DF indicating that several follicles have the capacity for dominance; therefore, it is proposed that the deviation process represents the entire mechanism of follicle selection in mares.
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Affiliation(s)
- O J Ginther
- Eutheria Foundation, Cross Plains, WI 53528, USA; Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, WI 53706, USA.
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Björkman S, Yun J, Niku M, Oliviero C, Soede NM, Peltoniemi OAT. Serial transvaginal ultrasound-guided biopsy of the porcine corpus luteum in vivo. Reprod Fertil Dev 2017; 29:931-939. [DOI: 10.1071/rd15435] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2015] [Accepted: 01/08/2016] [Indexed: 11/23/2022] Open
Abstract
The aims of the present study was to develop and describe a transvaginal ultrasound-guided biopsy method for luteal tissue in the porcine and to evaluate the effects of the method on the reproductive tract, ovarian status and pregnancy status. Biopsies were performed in four multiparous sows on Days 9 and 15 of three consecutive oestrous cycles; the size and histological composition of the samples obtained were evaluated and the reproductive tract of the sows was monitored. Furthermore, biopsies were performed in 26 multiparous sows on Days 10 and 13 after insemination, and the pregnancy rate, gestation length and subsequent litter size were evaluated. RNA was extracted from the samples obtained and the quality and quantity were determined. Altogether, 76 biopsies were performed and 38 samples were obtained. Compared with sows from which no samples were obtained (n = 6), sows from which one or more samples were obtained (n = 24) were older (parity 5.0 ± 2.8 vs 2.2 ± 0.4, mean ± s.d.), heavier (290 ± 26 vs 244 ± 27 kg) and had higher back fat (11.4 ± 2.7 vs 6.4 ± 2.5 mm; P < 0.05 for all). No effect of the biopsies (P > 0.05) was observed on the cyclicity and reproductive organs of the sows, or on corpus luteum diameter on Day 13 (8.9 ± 1.0 vs 9.2 ± 1.1 mm), pregnancy rate (95% vs 96%), gestation length (115 ± 1 vs 115 ± 1 days) and subsequent litter size (12.7 ± 2.5 vs 13.3 ± 2.8) between sows from which samples were obtained and those from which no samples were obtained. The samples obtained had a diameter of 1 mm and contained heterogeneous tissue with various cell types. The RNA quantity was 520 ± 160 µg per sample and the RNA integrity number was 8.5 ± 1.0. In conclusion, an ultrasound-guided biopsy method for ovarian tissue, which can be used for gene expression studies, was established in the porcine. No effect on corpus luteum function was found.
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Kozai K, Tokuyama S, Szóstek AZ, Toishi Y, Tsunoda N, Taya K, Sakatani M, Takahashi M, Nambo Y, Skarzynski DJ, Yamamoto Y, Kimura K, Okuda K. Evidence for a PGF2α auto-amplification system in the endometrium in mares. Reproduction 2016; 151:517-26. [PMID: 26908917 DOI: 10.1530/rep-15-0617] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2014] [Accepted: 02/22/2016] [Indexed: 11/08/2022]
Abstract
In mares, prostaglandin F2α (PGF2α) secreted from the endometrium is a major luteolysin. Some domestic animals have an auto-amplification system in which PGF2α can stimulate its own production. Here, we investigated whether this is also the case in mares. In an in vivo study, mares at the mid-luteal phase (days 6-8 of estrous cycle) were injected i.m. with cloprostenol (250 µg) and blood samples were collected at fixed intervals until 72 h after treatment. Progesterone (P4) concentrations started decreasing 45 min after the injection and continued to decrease up to 24 h (P < 0.05). In turn, 13,14-dihydro-15-keto-PGF2α (PGFM) metabolite started to increase 4h after an injection and continued to increase up to 72 h (P < 0.05). PGF receptor (PTGFR) mRNA expression in the endometrium was significantly higher in the late luteal phase than in the early and regressed luteal phases (P < 0.05). In vitro, PGF2α significantly stimulated (P < 0.05) PGF2α production by endometrial tissues and endometrial epithelial and stromal cells and significantly increased (P < 0.05) the mRNA expression of prostaglandin-endoperoxide synthase-2 (PTGS2), an enzyme involved in PGF2α synthesis in endometrial cell. These findings strongly suggest the existence of an endometrial PGF2α auto-amplification system in mares.
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Affiliation(s)
- Keisuke Kozai
- Laboratory of Reproductive PhysiologyGraduate School of Environmental and Life Science, Okayama University, Okayama, Japan
| | - Shota Tokuyama
- Laboratory of Reproductive PhysiologyGraduate School of Environmental and Life Science, Okayama University, Okayama, Japan
| | - Anna Z Szóstek
- Laboratory of Reproductive PhysiologyGraduate School of Environmental and Life Science, Okayama University, Okayama, Japan Department of Reproductive ImmunologyInstitute of Animal Reproduction and Food Research, Polish Academy of Sciences, Olsztyn, Poland
| | | | | | | | - Miki Sakatani
- Kyushu Okinawa Agricultural Research CenterNational Agriculture and Food Research Organization (NARO), Kumamoto, Japan
| | - Masashi Takahashi
- Kyushu Okinawa Agricultural Research CenterNational Agriculture and Food Research Organization (NARO), Kumamoto, Japan Department of Animal ScienceHokkaido University, Hokkaido, Japan
| | - Yasuo Nambo
- Equine Science DivisionHidaka Training and Research Center, Japan Racing Association, Hokkaido, Japan Obihiro University of Agriculture and Veterinary MedicineObihiro, Japan
| | - Dariusz J Skarzynski
- Department of Reproductive ImmunologyInstitute of Animal Reproduction and Food Research, Polish Academy of Sciences, Olsztyn, Poland
| | - Yuki Yamamoto
- Laboratory of Reproductive PhysiologyGraduate School of Environmental and Life Science, Okayama University, Okayama, Japan
| | - Koji Kimura
- Laboratory of Reproductive PhysiologyGraduate School of Environmental and Life Science, Okayama University, Okayama, Japan
| | - Kiyoshi Okuda
- Laboratory of Reproductive PhysiologyGraduate School of Environmental and Life Science, Okayama University, Okayama, Japan Obihiro University of Agriculture and Veterinary MedicineObihiro, Japan
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Maia VN, Batista AM, Cunha Neto S, Silva DMF, Adrião M, Wischral A. Expression of angiogenic factors and luteinizing hormone receptors in the corpus luteum of mares induced to ovulate with deslorelin acetate. Theriogenology 2015; 85:461-5. [PMID: 26476595 DOI: 10.1016/j.theriogenology.2015.09.025] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Revised: 09/09/2015] [Accepted: 09/09/2015] [Indexed: 12/27/2022]
Abstract
The effects of deslorelin acetate use in inducing ovulation need to be clarified to improve the results of equine embryo transfer. The mRNA abundance for angiogenic factors and LH receptor (LHR) in corpus luteum (CL) was studied in mares with natural (control group [CG]) and induced ovulation with deslorelin acetate (treatment group [TG]; follicles: ≥ 35 mm). Transrectal ultrasonography was used to verify the ovulation day, and on Days 4, 8, and 12 after ovulation (Day 0), CL samples were obtained through ultrasound-guided biopsy. The messenger RNA expression of vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), and LHR genes were analyzed by real-time polymerase chain reaction. A positive correlation was observed between VEGF and LHR (P < 0.00001, r = 0.78), and it was possible to detect higher LHR expression in the TG than in the CG on Day 4 (P < 0.05). Moreover, this expression was higher on Days 4 and 8 than on Day 12 in the TG. Basic fibroblast growth factor was also expressed in luteal tissue on all days for both groups; however, these differences were not significant. In conclusion, deslorelin acetate was effective for the induction of ovulation in mares, resulting in higher expression of LHR, especially on the fourth day after ovulation. In addition, VEGF expression was influenced by induced ovulation, with a lower level on Day 12, which is expected in nonpregnant mares.
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Affiliation(s)
- Victor N Maia
- Mauricio de Nassau University, Recife, Pernambuco, Brazil
| | - André M Batista
- Department of Veterinary Medicine, Federal Rural University of Pernambuco, Recife, Pernambuco, Brazil
| | | | - Diogo M F Silva
- Department of Animal Morphology and Physiology, Federal Rural University of Pernambuco, Recife, Pernambuco, Brazil
| | - Manoel Adrião
- Department of Animal Morphology and Physiology, Federal Rural University of Pernambuco, Recife, Pernambuco, Brazil
| | - Aurea Wischral
- Department of Veterinary Medicine, Federal Rural University of Pernambuco, Recife, Pernambuco, Brazil.
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Ginther OJ. How ultrasound technologies have expanded and revolutionized research in reproduction in large animals. Theriogenology 2014; 81:112-25. [PMID: 24274416 DOI: 10.1016/j.theriogenology.2013.09.007] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2013] [Revised: 09/06/2013] [Accepted: 09/07/2013] [Indexed: 01/26/2023]
Abstract
Gray-scale ultrasonic imaging (UI) was introduced in 1980 and initially was used to examine clinically the reproductive tract of mares. By 1983 in mares and 1984 in heifers/cows, UI had become a tool for basic research. In each species, transrectal gray-scale UI has been used extensively to characterize follicle dynamics and investigate the gonadotropic control and hormonal role of the follicles. However, the use of transrectal UI has also disclosed and characterized many other aspects of reproduction in each species, including (1) endometrial echotexture as a biological indicator of circulating estradiol concentrations, (2) relative location of the genital tubercle for fetal gender diagnosis by Days 50 to 60, and (3) timing of follicle evacuation during ovulation. Discoveries in mares include (1) embryo mobility wherein the spherical conceptus (6-16 mm) travels to all parts of the uterus on Days 11 to 15, (2) how one embryo of a twin set eliminates the other without self-inflicted damage, and (3) serration of the granulosum of the preovulatory follicle opposite to the future rupture site as an indicator of imminent ovulation. Studies with color-Doppler UI have shown that vascular perfusion of the endometrium follows the equine embryo back and forth between uterine horns and follows the expansion of the bovine allantochorion throughout each horn. In heifers, blood flow in the CL increases during the ascending portion of an individual pulse of PGF2α metabolite and then decreases. These examples highlight the power of UI in reproduction research. Without UI, it is likely that these and many other findings would still be unknown.
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Affiliation(s)
- O J Ginther
- Eutheria Foundation, Cross Plains, Wisconsin, USA; Department of Pathobiological Sciences, University of Wisconsin-Madison, Madison, Wisconsin, USA.
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14
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Haag K, Magalhães-Padilha D, Fonseca G, Wischral A, Gastal M, King S, Jones K, Figueiredo J, Gastal E. Quantification, morphology, and viability of equine preantral follicles obtained via the Biopsy Pick-Up method. Theriogenology 2013; 79:599-609. [DOI: 10.1016/j.theriogenology.2012.11.012] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2012] [Revised: 11/03/2012] [Accepted: 11/12/2012] [Indexed: 11/25/2022]
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15
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Ginther OJ, Beg MA. Dynamics of circulating progesterone concentrations before and during luteolysis: a comparison between cattle and horses. Biol Reprod 2012; 86:170. [PMID: 22460665 DOI: 10.1095/biolreprod.112.099820] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
The profile of circulating progesterone concentration is more dynamic in cattle than in horses. Greater prominence of progesterone fluctuations in cattle than in horses reflect periodic interplay in cattle between pulses of a luteotropin (luteinizing hormone; LH) and pulses of a luteolysin (prostaglandin F2alpha; PGF2alpha). A dose of PGF2alpha that induces complete regression of a mature corpus luteum with a single treatment in cattle or horses is an overdose. The overdose effects on the progesterone profile in cattle are an immediate nonphysiological increase taking place over about 30 min, a decrease to below the original concentration, a dose-dependent rebound 2 h after treatment, and a progressive decrease until the end of luteolysis. An overdose of PGF2alpha in horses results in a similar nonphysiological increase in progesterone followed by complete luteolysis; a rebound does not occur. An overdose of PGF2alpha and apparent lack of awareness of the rebound phenomenon has led to faulty interpretations on the nature of spontaneous luteolysis. A transient progesterone suppression and a transient rebound occur within the hours of a natural PGF2alpha pulse in cattle but not in horses. Progesterone rebounds are from the combined effects of an LH pulse and the descending portion of a PGF2alpha pulse. A complete transitional progesterone rebound occurs at the end of preluteolysis and the beginning of luteolysis and returns progesterone to its original concentration. It is proposed that luteolysis does not begin in cattle until after the transitional rebound. During luteolysis, rebounds are incomplete and gradually wane. A partial rebound during luteolysis in cattle is associated with a concomitant increase in luteal blood flow. A similar increase in luteal blood flow does not occur in mares.
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Affiliation(s)
- O J Ginther
- Eutheria Foundation, Cross Plains, Wisconsin, USA.
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16
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Atli MO, Bender RW, Mehta V, Bastos MR, Luo W, Vezina CM, Wiltbank MC. Patterns of gene expression in the bovine corpus luteum following repeated intrauterine infusions of low doses of prostaglandin F2alpha. Biol Reprod 2012; 86:130. [PMID: 22262696 DOI: 10.1095/biolreprod.111.094870] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
Natural luteolysis involves multiple pulses of prostaglandin F2alpha (PGF) released by the nonpregnant uterus. This study investigated expression of 18 genes from five distinct pathways, following multiple low-dose pulses of PGF. Cows on Day 9 of the estrous cycle received four intrauterine infusions of 0.25 ml of phosphate-buffered saline (PBS) or PGF (0.5 mg of PGF in 0.25 ml of PBS) at 6-h intervals. A luteal biopsy sample was collected 30 min after each PBS or PGF infusion. There were four treatment groups: Control (n = 5; 4 PBS infusions), 4XPGF (4 PGF infusions; n = 5), 2XPGF-non-regressed (2 PGF infusions; n = 5; PGF-PBS-PGF-PBS; no regression after treatments), and 2XPGF-regressed (PGF-PBS-PGF-PBS; regression after treatments; n = 5). As expected, the first PGF pulse increased mRNA for the immediate early genes JUN, FOS, NR4A1, and EGR1 but unexpectedly also increased mRNA for steroidogenic (STAR) and angiogenic (VEGFA) pathways. The second PGF pulse induced immediate early genes and genes related to immune system activation (IL1B, FAS, FASLG, IL8). However, mRNA for VEGFA and STAR were decreased by the second PGF infusion. After the third and fourth PGF pulses, a distinctly luteolytic pattern of gene expression was evident, with inhibition of steroidogenic and angiogenic pathways, whereas, there was induction of pathways for immune system activation and production of PGF. The pattern of PGF-induced gene expression was similar in corpus luteum not destined for luteolysis (2X-non-regressed) after the first PGF pulse but was very distinct after the second PGF pulse. Thus, although the initial PGF pulse induced mRNA for many pathways, the second and later pulses of PGF appear to have set the distinct pattern of gene expression that result in luteolysis.
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Affiliation(s)
- Mehmet O Atli
- Endocrinology-Reproductive Physiology Program and Department of Dairy Science, University of Wisconsin, Madison, Wisconsin, USA
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17
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Kozai K, Hojo T, Takahashi M, Acosta TJ, Nambo Y, Okuda K. Seasonal changes in luteal progesterone concentration and mRNA expressions of progesterone synthesis-related proteins in the corpus luteum of mares. J Reprod Dev 2012; 58:393-7. [PMID: 22498814 DOI: 10.1262/jrd.2012-023] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Although circulating progesterone (P₄) levels tend to change with the season, little is known about the seasonal changes of P₄ synthesis-related proteins in the corpus luteum (CL) of mares. To examine these changes, seventy-four ovaries containing a CL were collected from Anglo-Norman mares at a local abattoir in Kumamoto, Japan (~N32°), five times during one year. The stages of the CLs were classified as early, mid and regressed by macroscopic observation of the CL and follicles. The mid CL, which had the highest P₄ concentration, was used to evaluate the seasonal changes in P₄ synthesis. The luteal P₄ concentration and mRNA expression of luteinizing hormone receptor (LHCGR) were lowest during early winter and highest during late winter. The mRNA expressions of steroidogenic acute regulatory protein (StAR), P450 cholesterol side-chain cleavage enzyme (P450scc) and 3β-hydroxysteroid dehydrogenase/Δ5-Δ4 isomerase (3β-HSD) were lowest during early winter and increased during late winter. These results suggest that P₄ synthesis in the CL is affected by the seasonal changes in the mRNA expressions of P₄ synthesis-related proteins in mares.
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Affiliation(s)
- Keisuke Kozai
- Laboratory of Reproductive Physiology, Graduate School of Natural Science and Technology, Okayama University, Okayama 700-8530, Japan
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Galvão A, Skarzynski D, Szóstek A, Silva E, Tramontano A, Mollo A, Mateus L, Ferreira-Dias G. Cytokines tumor necrosis factor-α and interferon-γ participate in modulation of the equine corpus luteum as autocrine and paracrine factors. J Reprod Immunol 2012; 93:28-37. [DOI: 10.1016/j.jri.2011.11.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2011] [Revised: 11/25/2011] [Accepted: 11/27/2011] [Indexed: 11/29/2022]
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19
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Slough TL, Rispoli LA, Carnevale EM, Niswender GD, Bruemmer JE. Temporal gene expression in equine corpora lutea based on serial biopsies in vivo1. J Anim Sci 2011; 89:389-96. [DOI: 10.2527/jas.2010-3247] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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20
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Ginther O. A 40-year odyssey into the mysteries of equine luteolysis. Theriogenology 2009; 72:591-8. [DOI: 10.1016/j.theriogenology.2009.05.016] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2009] [Revised: 05/14/2009] [Accepted: 05/17/2009] [Indexed: 10/20/2022]
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21
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Early conception factor lateral flow assays for pregnancy in the mare. Theriogenology 2009; 71:877-83. [DOI: 10.1016/j.theriogenology.2008.06.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2007] [Revised: 03/11/2008] [Accepted: 06/03/2008] [Indexed: 11/22/2022]
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Ginther OJ, Siddiqui MAR, Beg MA. Progesterone responses to intravenous and intrauterine infusions of prostaglandin F2α in mares. Reprod Fertil Dev 2009; 21:688-95. [DOI: 10.1071/rd09019] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2009] [Accepted: 04/02/2009] [Indexed: 11/23/2022] Open
Abstract
The hypotheses were tested that prostaglandin F2α (PGF) travels from the uterus to the ovaries via a systemic route in mares, as opposed to a local route in ruminants, and that one pulse of PGF produces only partial luteolysis. Intravenous (i.v.) and intrauterine (i.u.) infusions of PGF were performed 8 days after ovulation at a constant rate for 2 h. Plasma concentrations of PGF were assessed by assay of 13,14-dihydro-15-keto-PGF2α (PGFM). Total doses administered were as follows: 0, 0.05, 0.1, 0.5 and 1.0 mg, i.v., PGF and 0 and 0.5 mg, i.u., PGF (n = 4 mares per group). In addition, PGFM concentrations were determined for natural pulses from samples collected each hour during luteolysis (n = 5). Progesterone was similarly reduced by 4 days after treatment in the 0.5 mg i.v., 0.5 mg i.u. and 0.0 mg i.u. groups. The area under the PGFM curve in the 0.1 mg i.v. group was similar to the area for natural PGFM pulses. Progesterone decreased to a similar concentration by 12 h in the 0.1, 0.5 and 1.0 mg i.v. groups, but thereafter was greater (P < 0.05) in the 0.1 mg i.v. group. Progesterone concentrations reached <2 ng mL–1 6 days after treatment in the 0.05 and 0.1 mg i.v. groups and 2 days after treatment in the 0.5 and 1.0 mg i.v. groups. The results support the hypotheses of a systemic uteroluteal route for PGF transfer and that one pulse produces only partial luteolysis in mares.
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Ginther OJ, Rodrigues BL, Ferreira JC, Araujo RR, Beg MA. Characterisation of pulses of 13,14-dihydro-15-keto-PGF2alpha (PGFM) and relationships between PGFM pulses and luteal blood flow before, during, and after luteolysis in mares. Reprod Fertil Dev 2008; 20:684-93. [PMID: 18671916 DOI: 10.1071/rd08077] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2008] [Accepted: 05/26/2008] [Indexed: 11/23/2022] Open
Abstract
Blood collections for characterising 13,14-dihydro-15-keto-PGF2alpha (PGFM) pulses in mares and colour-Doppler examinations for estimating percentage of corpus luteum with blood-flow signals were done hourly for a 24-h session on Day 15 (ovulation = Day 0; n = 13 mares) or during 12-h sessions from Days 12 to 16 (n= 10 mares). Luteolysis was defined as extending from the beginning of a precipitous decrease in progesterone until progesterone was <2 ng mL(-1). Comparisons were made among preluteolysis, luteolysis, and postluteolysis. Greater prostaglandin F2alpha activity (mean PGFM concentration per session) occurred during luteolysis than during preluteolysis and postluteolysis. Statistically-detected PGFM pulses were smaller during preluteolysis with a highly variable interval from the last pulse to the beginning of luteolysis. Either two or three pulses were detected in each 24-h session during luteolysis and postluteolysis, after excluding three of eight sessions with no pulses during postluteolysis. Statistically, 17% of pulses during postluteolysis were prominent outliers. The nadir-to-nadir interval during a pulse (5 h), the peak-to-peak interval between pulses (9 h), and the resulting 4-h gap between pulses were similar during and after luteolysis. The decrease in progesterone encompassed the PGFM pulses, without a detectable fluctuation during a pulse. The percentage of corpus luteum with blood-flow signals did not change during the ascending portion of a PGFM pulse and decreased within 2 or 3 h after the peak, even during preluteolysis. Results indicated that a reported increase in luteal blood flow in heifers during the ascending portion of a PGFM pulse does not occur in mares.
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Affiliation(s)
- O J Ginther
- Eutheria Foundation, Cross Plains, WI 53528, USA.
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24
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Ginther OJ, Gastal EL, Gastal MO, Beg MA. Effect of prostaglandin F2alpha on ovarian, adrenal, and pituitary hormones and on luteal blood flow in mares. Domest Anim Endocrinol 2007; 32:315-28. [PMID: 16698221 DOI: 10.1016/j.domaniend.2006.04.006] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/06/2006] [Revised: 04/10/2006] [Accepted: 04/12/2006] [Indexed: 11/20/2022]
Abstract
The effect of a single injection of prostaglandin F2alpha (PGF) during mid-diestrus on systemic concentrations of progesterone, LH, FSH, estradiol, and cortisol and on blood flow to the corpus luteum was studied in 10 controls and 10 PGF-treated mares. Blood flow was assessed by estimating the percentage of corpus luteum with color-Doppler signals of blood flow during real-time scanning of the entire structure and by the diameter of the vascular pedicle near its attachment to the ovary. Treatment was done 8 days after ovulation and 0 h was immediately before the treatment. Examinations and collection of blood samples were done at 0 h, every 5 min until 1h, and then at 1.5, 2, 4, 8, 12, 24, 48, and 72 h. The concentrations of estradiol did not change, but progesterone, LH, FSH, and cortisol increased significantly within 5 min. Concentrations of LH and FSH in the PGF group remained elevated until a temporarily lower concentration at 8 or 4h, respectively, rebounded to 12h, and then slowly decreased. Cortisol remained elevated, until a decrease between 1 and 4h. Progesterone in the PGF group increased significantly until 10 min after 0 h and then decreased by 40 min to below the concentrations in controls. Within the PGF group, progesterone decreased significantly by 45 min to below the concentrations at 0 h. The values for each of the two indicators of blood flow did not differ significantly between the PGF and control groups until a decrease at 24h in the PGF group. Results did not support the hypothesis that the immediate transient post-PGF increase in progesterone was associated with an increase in luteal blood flow. Luteolysis, as indicated by decreasing progesterone, began well before the beginning of a decrease in luteal blood flow.
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Affiliation(s)
- O J Ginther
- Eutheria Foundation, Cross Plains, WI 53528, United States.
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Aguilar J, Fraser HM, Wilson H, Clutton E, Shaw DJ, Watson ED. Temporal relationship between proliferating and apoptotic hormone-producing and endothelial cells in the equine corpus luteum. Reproduction 2006; 132:111-8. [PMID: 16816337 DOI: 10.1530/rep.1.01051] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The temporal relationship between endothelial cell death, vascular regression and the death of hormone-producing cells in the mare has not been established. To determine the dynamics of cell proliferation and death throughout the luteal phase, corpora lutea were studied at the early, mid- and late luteal phase, and after treatment with cloprostenol in the mid-luteal phase to induce premature luteolysis. Changes in cell proliferation and apoptosis were investigated utilising specific markers (phosphorylated histone-3 and activated caspase-3 respectively). Histone-3 positive cells were most abundant during the early luteal phase, and were mainly present in endothelial cells. Histone-3 activity significantly increased in hormone-producing cells 36 h after cloprostenol treatment. Frequency of activated caspase-3 staining peaked on day 14, and was induced by 36 h after cloprostenol administration in mid-luteal phase. However, cell death occurred simultaneously in the endothelial and hormone-producing cells. These results show that a subset of hormone-producing cells enter the early stages of cell division around luteolysis, while the majority of cells are undergoing cell death. Natural and induced functional and structural luteal regression in the mare can be at least partially attributed to simultaneous apoptosis of endothelial and hormone-producing cells. However, there is no evidence that endothelial cell death is the trigger for naturally occurring luteolysis.
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Affiliation(s)
- J Aguilar
- Division of Veterinary Clinical Studies, Royal (Dick) School of Veterinary Studies, University of Edinburgh, Roslin, Midlothian EH25 9RG, UK.
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Sayasith K, Bouchard N, Doré M, Sirois J. Molecular cloning and gonadotropin-dependent regulation of equine prostaglandin F2α receptor in ovarian follicles during the ovulatory process in vivo. Prostaglandins Other Lipid Mediat 2006; 80:81-92. [PMID: 16846789 DOI: 10.1016/j.prostaglandins.2006.05.020] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2006] [Accepted: 05/15/2006] [Indexed: 10/24/2022]
Abstract
The progressive rise in gonadotropins prior to ovulation triggers a marked increase in intrafollicular levels of prostaglandin F(2alpha)(PGF(2alpha)), which is known to interact with PGF(2alpha) receptor (FP). Little is known about the regulation of FP during ovulation. This study was undertaken to characterize the equine FP and its gonadotropin-dependent regulation in preovulatory follicles prior to ovulation. The full-length equine FP encodes a 366-amino acid protein that is 82-93% homologous to other species. Using semi-quantitative RT-PCR/Southern blot, we showed that FP mRNA expression was low in follicles obtained before hCG treatment (0h) and at 24, but increased at 12 and 36h post-hCG (P<0.05). This expression was regulated in both follicular cells, with high levels of the transcript at 33 and 36h post-hCG in granulosa cells, and at 12, 30 and 33h post-hCG in theca cells (P<0.05). Immunohistochemistry confirmed the induction of FP protein in both follicular cells after hCG, and immunoblotting revealed the increase of FP protein in preovulatory follicles 36h post-hCG. High levels of FP mRNA were detected in the corpora lutea and heart, but very low or undetectable in other tissues. This study reports for the first time the expression of FP and its up-regulation by hCG in preovulatory follicles prior to ovulation. FP regulation was occurred in different pattern than that observed in other species, suggesting a distinct and species-specific follicular control of FP expression during ovulation, and a potential involvement of PGF(2alpha), acting on granulosa and theca cells, in the ovulatory process.
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Affiliation(s)
- Khampoune Sayasith
- Centre de Recherche en Reproduction Animale and Département de Biomédecine Vétérinaire, Faculté de Médecine Vétérinaire, Université de Montréal, Saint-Hyacinthe, Qué. J2S 7C6, Canada.
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27
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Utt MD, Acosta TJ, Wiltbank MC, Ginther OJ. Acute effects of prostaglandin F(2alpha) on systemic oxytocin and progesterone concentrations during the mid- or late-luteal phase in mares. Anim Reprod Sci 2006; 97:63-73. [PMID: 16500050 DOI: 10.1016/j.anireprosci.2006.01.009] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2005] [Accepted: 01/17/2006] [Indexed: 10/25/2022]
Abstract
The acute effects of prostaglandin F(2alpha) (PGF) on circulating oxytocin and progesterone concentrations were characterized in mares during the mid- or late-luteal phase. Pony mares were randomly assigned to the following experimental groups based on treatment with PGF (2.5mg) or saline on Day 8 or Day 13 (Day 0=ovulation): PGF-8, PGF-13, saline-8, or saline-13 (n=7/group). Mares were fitted with indwelling, jugular vein catheters and two blood samples (-5 and 0 min) were collected prior to treatment. Treatments were administered into the jugular vein (0 min) and blood collection continued thereafter at 1 min intervals until 5 min and then at 5 min intervals until 60 min. Based on the combined data of -5 and 0 min samples, mares on Day 8 had greater (P<0.05) oxytocin concentrations than mares on Day 13. On Day 8, PGF treatment resulted in a biphasic pattern of oxytocin release. Oxytocin concentrations increased (P<0.05) 1 min after PGF treatment, decreased (P<0.05) from 1 to 10 min, and increased (P<0.05) from 10 to 30 min. Oxytocin concentrations were greater (P<0.05) from 1 to 3 min in PGF-treated than saline-treated mares and at most sample times from 15 to 60 min. On Day 13, oxytocin concentrations were greater (P<0.05) in PGF-treated than in saline-treated mares for most sample times. Mares treated with PGF on Day 8 had greater (P<0.05) oxytocin concentrations at 25, 30, and 40 min than mares on Day 13. Progesterone concentrations on Day 8 also increased by 1 min after PGF, decreased toward basal concentrations by 2-3 min, and then increased to a maximum 10 min after treatment. Subsequently, circulating progesterone decreased (P<0.05) below pretreatment concentrations by 40-50 min after PGF. In conclusion, treatment with PGF resulted in an immediate and biphasic increase in progesterone concentrations prior to the expected decrease. Treatment of mares with PGF on Day 8 resulted in an overall greater increase in systemic oxytocin concentrations compared to treatment on Day 13, and the increase on Day 8 was biphasic.
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Affiliation(s)
- M D Utt
- Department of Animal Health and Biomedical Sciences, University of Wisconsin, Madison 53706, USA
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