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Rio Feltrin I, Guimarães da Silva A, Rocha CC, Ferraz PA, da Silva Rosa PM, Martins T, Coelho da Silveira J, Oliveira ML, Binelli M, Pugliesi G, Membrive CMB. Effects of 17β-estradiol on the uterine luteolytic cascade in bovine females at the end of diestrus. Theriogenology 2024; 213:1-10. [PMID: 37783065 DOI: 10.1016/j.theriogenology.2023.09.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Revised: 09/19/2023] [Accepted: 09/24/2023] [Indexed: 10/04/2023]
Abstract
In cattle, 17β-estradiol (E2) is essential for triggering luteolysis via the synthesis of prostaglandin F2α (PGF2α). We aimed to evaluate the effects of E2-treatment on day 15 of the estrous cycle on the transcript abundance of genes involved in the PGF2α synthetic cascade. Nelore heifers (N = 50) were subjected to a hormonal protocol for the synchronization of ovulation. Between days 14 and 23 after estrus, the area (cm2) and blood perfusion (%) of the corpus luteum (CL) and progesterone (P4) plasma concentrations were evaluated daily. On day 15, the heifers were assigned to the Control (2 mL of pure sesame oil, N = 21) or Estradiol group (1 mg of E2 diluted in 2 mL of sesame oil, N = 23). After the treatments at 0 h, uterine biopsies were collected at times 1.5 h (C1.5h, N = 8 and E1.5h, N = 10) or 3 h (C3h, N = 8 and E3h, N = 11); and blood samples were obtained from 0, 3, 4, 6 and 7 h for the measurement of 13,14-dihydro-15-keto-PGF2α (PGFM) concentrations by ELISA. Transcript abundance was determined by RT-qPCR and protein abundance of ESRβ and OXTR was determined by Western Blotting. The Estradiol group showed greater (P < 0.05) concentrations of PGFM at 6 and 7 h compared to the Control group. A progressive decrease in plasma P4 concentrations characterized a hastened functional luteolysis, followed by structural luteolysis in the Estradiol group (P < 0.05). Among the treatment groups, no significant difference was detected for the abundance of PRKCα, PRKCβ, AKR1B1, PTGS2 and ESRα transcripts (P > 0.05). Estradiol treatment decreased the abundance of PLA2G4A, AKR1C4, and ESRβ both 1.5h and 3h after treatment (P < 0.05). The relative expression of PGR and OXTR was greater in E3h compared to the C3h (P > 0.05). Protein abundance did not differ between treatment groups at either experimental times (P > 0.05). Overall, E2 promoted an increase in PGFM concentrations and the hastening of functional and structural luteolysis in Nelore heifers through the upregulation of PGR and OXTR, demonstrating for the first time that the expression of these receptors within 3 h after E2 stimulus was associated with triggering luteolysis in cattle.
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Affiliation(s)
- Isabella Rio Feltrin
- Department of Pharmacology and Biotechnology, São Paulo State University - UNESP, Botucatu, SP, Brazil.
| | | | | | - Priscila Assis Ferraz
- Department of Animal Reproduction, University of São Paulo - USP, Pirassununga, SP, Brazil
| | - Paola Maria da Silva Rosa
- Faculty of Animal Science and Food Engineering, Department of Veterinary Medicine, University of São Paulo - USP, Pirassununga, SP, Brazil
| | - Thiago Martins
- Departament of Animal and Dairy Sciences and Brown Loam Experiment Station, Mississipi State University, Raymond, Mississipi, USA
| | - Juliano Coelho da Silveira
- Faculty of Animal Science and Food Engineering, Department of Veterinary Medicine, University of São Paulo - USP, Pirassununga, SP, Brazil
| | - Milena Lopes Oliveira
- Agrarian Sciences Center, State University of Maranhão Tocantins Region, Imperatriz, MA, Brazil
| | - Mario Binelli
- Department of Animal Sciences, University of Florida - UF, Gainesville, FL, USA
| | - Guilherme Pugliesi
- Department of Animal Reproduction, University of São Paulo - USP, Pirassununga, SP, Brazil
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Comparison of estradiol benzoate doses for resynchronization of ovulation at 14 days after timed-AI in suckled beef cows. Theriogenology 2022; 184:41-50. [DOI: 10.1016/j.theriogenology.2022.02.025] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Revised: 02/03/2022] [Accepted: 02/26/2022] [Indexed: 01/01/2023]
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Oliveira ML, Mello BP, Gonella-Diaza AM, Scolari SC, Pugliesi G, Martins T, Feltrin IR, Sartori R, Canavessi AMO, Binelli M, Membrive CMB. Unravelling the role of 17β-estradiol on advancing uterine luteolytic cascade in cattle. Domest Anim Endocrinol 2022; 78:106653. [PMID: 34455235 DOI: 10.1016/j.domaniend.2021.106653] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Revised: 07/21/2021] [Accepted: 07/27/2021] [Indexed: 01/10/2023]
Abstract
In cattle, 17β-estradiol (E2) stimulates prostaglandin F2α (PGF2α) synthesis, which causes luteolysis. Except for the well-established upregulation of oxytocin receptor gene (OXTR), molecular mechanisms of E2-induced PGF2α release in vivo remain unknown. We hypothesized that E2-induced PGF2α release requires de novo transcription of components of the PGF2α synthesis machinery. Beef cows (n = 52) were assigned to remain untreated (Control; n = 10), to receive 50% ethanol infusion intravenously (Placebo; n = 21), or 3 mg E2 in 50% ethanol infusion intravenously (Estradiol; n = 21) on day 15 (D15) after estrus. We collected a single endometrial biopsy per animal at the time of the treatment (0h; Control B0h group), 4 hours (4h; Placebo B4h group and Estradiol B4h group), or 7 hours (7h; Placebo B7h group and Estradiol B7h group) post-treatment. Compared to the Placebo group, the Estradiol group presented significantly greater 13,14-dihydro-15-keto-PGF2α concentrations between 4h and 7h and underwent earlier luteolysis. At 4h, the qPCR analysis showed a lower abundance of ESR1, ESR2 and aldo-keto reductase family 1 member B1 (AKR1B1) genes in the Estradiol B4h group, and a greater abundance of OXTR compared to the Placebo B4h group. Similarly, the E2 treatment significantly reduced the abundance of AKR1B1, and AKR1C4 in the Estradiol B7h group, compared to the placebo group. Overall, E2-induced PGF2α release and luteolysis involved an unexpected and transient downregulation of components of the PGF2α-synthesis cascade, except for OXTR, which was upregulated. Collectively, our data suggest that E2 connects newly-synthesized OXTR to pre-existing cellular machinery to synthesize PGF2α and cause luteal regression.
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Affiliation(s)
- M L Oliveira
- Agrarian Sciences Center, State University of Maranhão Tocantine Region, 1300 Godofredo Viana St, Center, Imperatriz - MA, 65900-000, Brazil..
| | - B P Mello
- Department of Animal Reproduction, University of São Paulo, 225 Duque de Caxias Norte Ave, Pirassununga - SP, 13635900, Brazil
| | - A M Gonella-Diaza
- North Florida Research and Education Center, Institute of Food and Agricultural Sciences, University of Florida, 3925 FL-71, Greenwood, FL 32443, USA
| | - S C Scolari
- Department of Animal Reproduction, University of São Paulo, 225 Duque de Caxias Norte Ave, Pirassununga - SP, 13635900, Brazil
| | - G Pugliesi
- Department of Animal Reproduction, University of São Paulo, 225 Duque de Caxias Norte Ave, Pirassununga - SP, 13635900, Brazil
| | - T Martins
- Department of Animal Sciences, University of Florida, 2250 Shealy Dr, Gainesville, FL 32611, USA
| | - I R Feltrin
- Department of Pharmacology and Biotechnology, São Paulo State University, Rubião Júnior District no number, Botucatu-SP, 18618-970, Brazil
| | - R Sartori
- Department of Animal Science, Luiz de Queiroz College of Agriculture, University of São Paulo, 11, Pádua Dias Ave, Piracicaba-SP, 13418900, Brazil
| | - A M O Canavessi
- Department of Animal Science, Luiz de Queiroz College of Agriculture, University of São Paulo, 11, Pádua Dias Ave, Piracicaba-SP, 13418900, Brazil
| | - M Binelli
- Department of Animal Sciences, University of Florida, 2250 Shealy Dr, Gainesville, FL 32611, USA
| | - C M B Membrive
- Department of Animal Sciences, São Paulo State University, 294-SP Commander João Ribeiro de Barros, 651 Road, Dracena-SP, 17900000, Brazil
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Motta IG, Rocha CC, Bisinotto DZ, Melo GD, Júnior GAA, Nishimura TK, Diaza AMG, Castro T, Ginther OJ, Pugliesi G. Effects of estradiol treatments on PGF 2α release in beef heifers submitted to estrous resynchronization 14 days after timed-AI. Domest Anim Endocrinol 2021; 76:106625. [PMID: 33878540 DOI: 10.1016/j.domaniend.2021.106625] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 03/10/2021] [Accepted: 03/16/2021] [Indexed: 01/09/2023]
Abstract
The effects of 17β-estradiol (E2) or estradiol benzoate (EB) on PGF2α release were studied in bred-non-pregnant and pregnant Nelore beef heifers. The day of timed artificial insemination (TAI) was designated day 0 (D0), and a single treatment was given on D14. All heifers also received an intravaginal P4 device on D14, and were randomly assigned to three groups: Control (C, P4 device only, n = 12); E2 (1 mg E2 + 9 mg P4, n = 10); or EB (1 mg, n = 10). Blood samples were collected hourly for 8 hours after treatment (Hours 0-8) to measure plasma concentrations (pg/mL) of a PGF2α metabolite (PGFM). The P4 device was removed on D22 and pregnancy was diagnosed on D28. Pregnancy rate was not different among groups (C, n = 7/12; E2, n = 5/10; EB, n = 5/10). More (P < 0.05) heifers had a CV-identified prominent PGFM pulse (peak of > 100 pg/mL) in E2 group (6/10) than in EB (1/10) and C (0/12) groups. Hourly concentration of PGFM for Hours 0 to 8 showed significant effects of group and hour and an interaction of group by hour but did not show an interaction of group or hour with pregnancy status. In preliminary post-hoc analyses, PGFM concentrations during Hours 0 to 8 and pulse characteristics were analyzed within each pregnancy status. For the non-pregnant heifers, a group-by-hour interaction was detected tentatively indicating an increase (P < 0.005) in PGFM concentrations in E2 group from Hours 4 to 6 and in EB group at Hours 5 and 6. Maximum PGFM concentration during Hours 0 to 8 did not differ (P > 0.1) between E2 (124 ± 23) and EB (110 ± 30) groups, but was greater (P < 0.05) in each group than in C (32 ± 3). Furthermore, PGFM concentrations of pulses at the peak, amplitude, and area under pulse curve (pg/mL/h) were greater (P < 0.05) in E2 group than in C group whereas the EB group did not differ (P > 0.1) from the other groups. For pregnant heifers, no effects of group, hour, or their interaction were detected in PGFM concentrations during the hourly sessions, except that maximum PGFM concentration was greater (P < 0.05) in E2 than in EB and C groups. In addition, the number of prominent pulses was greater in E2 group than in Control or EB groups. In conclusion, PGFM increased earlier and in greater concentration combined for bred-non-pregnant and pregnant heifers treated 14 days after TAI with 1 mg E2 plus 9 mg P4 than with 1 mg EB. Tentatively, a positive effect for each of E2 and EB on PGFM concentrations was attenuated in pregnant heifers.
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Affiliation(s)
- I G Motta
- Department of Animal Reproduction, School of Veterinary Medicine and Animal Science, University of São Paulo, Pirassununga, São Paulo, Brazil
| | - C C Rocha
- Department of Animal Reproduction, School of Veterinary Medicine and Animal Science, University of São Paulo, Pirassununga, São Paulo, Brazil; North Florida Research and Education Center, University of Florida, FL, USA
| | - D Z Bisinotto
- Department of Animal Reproduction, School of Veterinary Medicine and Animal Science, University of São Paulo, Pirassununga, São Paulo, Brazil
| | - G D Melo
- Department of Animal Science - Texas A&M University of Texas, TX, USA
| | - G A A Júnior
- Department of Animal Reproduction, School of Veterinary Medicine and Animal Science, University of São Paulo, Pirassununga, São Paulo, Brazil
| | - T K Nishimura
- Department of Animal Reproduction, School of Veterinary Medicine and Animal Science, University of São Paulo, Pirassununga, São Paulo, Brazil
| | - A M G Diaza
- North Florida Research and Education Center, University of Florida, FL, USA
| | - T Castro
- Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, MDN, Wisconsin
| | - O J Ginther
- Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, MDN, Wisconsin
| | - G Pugliesi
- Department of Animal Reproduction, School of Veterinary Medicine and Animal Science, University of São Paulo, Pirassununga, São Paulo, Brazil.
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Motta IG, Rocha CC, Bisinotto DZ, Melo GD, Ataide Júnior GA, Silva AG, Gonzaga VHG, Santos JA, Freitas BG, Lemes KM, Madureira EH, Pugliesi G. Increased pregnancy rate in beef heifers resynchronized with estradiol at 14 days after TAI. Theriogenology 2020; 147:62-70. [PMID: 32097817 DOI: 10.1016/j.theriogenology.2020.02.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Revised: 02/06/2020] [Accepted: 02/06/2020] [Indexed: 10/25/2022]
Abstract
We aimed to evaluate the treatment with estradiol benzoate (EB) or 17β-estradiol (E2) associated with progesterone (P4) for resynchronization of ovulation 14 days after timed artificial insemination (TAI). In Experiment 1 (Exp. 1), Nelore heifers were submitted to TAI (D0). On D14, the animals received an intravaginal P4 device and were randomly assigned to one of three groups: control (no treatment; n = 17); EB (1 mg EB; n = 17); and E2+P4 (1 mg E2 + 9 mg P4; n = 18). Ultrasonography evaluations were performed daily from D14 to D22 to map follicular and luteal dynamics. On D22, the P4 devices were removed and non-pregnant (NP) animals were determined using corpus luteum blood flow Doppler ultrasonography. In Exp. 2, 1295 beef heifers were resynchronized and randomly allocated to the same experimental groups as described in Exp. 1. On D22, the largest follicle (LF) was measured in NP and a second TAI was performed on D24. In a subset of heifers (n = 337), an estrus detection patch was used between D22 and D24 to monitor estrus expression and the LF was measured at D24. Confirmatory diagnosis of pregnancy was performed between D37-67 and D43-67 after first and second TAI, respectively. In Exp 1, the proportion of heifers with a synchronized follicular wave emergence (from 3 to 5 days after treatment) was greater (P < 0.05) in the EB group (93.8%) than in the control (62.5%) and E2+P4 (64.7%) groups. Structural luteolysis occurred earlier (P < 0.05) in the EB and E2+P4 groups than in the controls. The pregnancy rate after first TAI did not differ (P > 0.1) among the groups at D22 and at confirmatory diagnosis in both experiments. In Exp 2, the potential pregnancy loss between D22 and D37-67 was similar (P > 0.1) in the control (19% [36/185]), EB (15% [28/182]) and E2+P4 (15% [28/184]) groups. The LF diameter (mm) on D22 was greater (P < 0.05) in the control group (11.9 ± 0.1) than in EB (11.3 ± 0.1) and E2+P4 (11.5 ± 0.1). No difference (P > 0.1) was observed in the proportion of heifers detected in estrus, but LF growth rate (mm/day) between D22 and D24 was greater (P < 0.05) in EB group (0.9 ± 0.08) than in control (0.6 ± 0.07) and E2+P4 (0.7 ± 0.09) groups. The pregnancy rate for the second TAI was greater (P < 0.05) in the EB group (47% [94/200]) than in the control (37% [76/203]), but did not differ (P > 0.1) from the E2+P4 group (43% [93/214]). In conclusion, the treatment with 1 mg EB or 1 mg E2 + 9 mg P4 at 14 days post-TAI anticipates luteolysis in NP heifers but does not compromise pregnancy. The EB treatment induces a new synchronized follicle wave emergence and increases the pregnancy rate of resynchronized NP heifers.
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Affiliation(s)
- I G Motta
- Department of Animal Reproduction, School of Veterinary Medicine and Animal Science, University of São Paulo, Pirassununga, São Paulo, Brazil
| | - C C Rocha
- Department of Animal Reproduction, School of Veterinary Medicine and Animal Science, University of São Paulo, Pirassununga, São Paulo, Brazil
| | - D Z Bisinotto
- Department of Animal Reproduction, School of Veterinary Medicine and Animal Science, University of São Paulo, Pirassununga, São Paulo, Brazil
| | - G D Melo
- Department of Animal Reproduction, School of Veterinary Medicine and Animal Science, University of São Paulo, Pirassununga, São Paulo, Brazil
| | - G A Ataide Júnior
- Department of Animal Reproduction, School of Veterinary Medicine and Animal Science, University of São Paulo, Pirassununga, São Paulo, Brazil
| | - A G Silva
- Department of Animal Reproduction, School of Veterinary Medicine and Animal Science, University of São Paulo, Pirassununga, São Paulo, Brazil
| | - V H G Gonzaga
- Department of Animal Reproduction, School of Veterinary Medicine and Animal Science, University of São Paulo, Pirassununga, São Paulo, Brazil
| | | | - B G Freitas
- Ourofino Saúde Animal, Cravinhos, São Paulo, Brazil
| | - K M Lemes
- Boehringer Ingelheim Animal Health do Brasil LTDA, São Paulo, São Paulo, Brazil
| | - E H Madureira
- Department of Animal Reproduction, School of Veterinary Medicine and Animal Science, University of São Paulo, Pirassununga, São Paulo, Brazil
| | - G Pugliesi
- Department of Animal Reproduction, School of Veterinary Medicine and Animal Science, University of São Paulo, Pirassununga, São Paulo, Brazil.
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Follicular dynamics, ovarian vascularity and luteal development in mares with early or late postpartum ovulation. Theriogenology 2017; 96:23-30. [DOI: 10.1016/j.theriogenology.2017.03.020] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2016] [Revised: 03/20/2017] [Accepted: 03/22/2017] [Indexed: 11/30/2022]
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Circulating nitric oxide metabolites during luteolysis and the effect of luteinizing hormone on circulating nitric oxide metabolites in heifers. Theriogenology 2015; 83:213-21. [PMID: 25442387 DOI: 10.1016/j.theriogenology.2014.09.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2014] [Revised: 09/02/2014] [Accepted: 09/10/2014] [Indexed: 11/23/2022]
Abstract
Temporal relationships among circulating concentrations of nitric oxide metabolites (NOM), progesterone (P4), and luteinizing hormone (LH) within the hours of a PGFM pulse were studied during luteolysis in heifers. The peak of a PGFM pulse was designated Hour 0. All of the following increases and decreases were significant. Within a spontaneous PGFM pulse (experiment 1; n = 7), concentrations of P4 and LH decreased between Hours -1 and 0 and increased between Hours 0 and 1; NOM increased between Hours -1 and 2. In experiment 2, PGFM pulses were simulated by intrauterine infusion of PGF2α (PGF group, n = 6), and another group was also treated with acyline to inhibit LH secretion (acyline-PGF group, n = 6). Averaged over the two groups, concentration of P4 decreased between Hours -2 and 0, increased (rebounded) between Hours 0 and 1, and decreased after Hour 2. In the PGF group, concentration of LH decreased between Hours -2 and -0.5 and increased between Hour 0 and Hour 1.5 to a maximum at Hour 1.5; NOM decreased between Hours -2 and -1.5 and increased between Hours 0 and 1.5. In the acyline-PGF group, the effect of hour was not significant for concentrations of LH and NOM. The absence of an increase in NOM concentration when LH was inhibited is a novel finding. The hypotheses were supported that concentrations of LH and NOM are temporally related, and LH has a role in the increase in NOM within the hours of a PGFM pulse.
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Ginther O, Bashir S, Mir R, Santos V, Beg M. Interrelationships among progesterone, LH, and luteal blood flow during a pulse of a PGF2α metabolite and functional role of LH in the progesterone rebound in heifers. Theriogenology 2013; 79:1110-9. [DOI: 10.1016/j.theriogenology.2013.02.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2012] [Revised: 02/05/2013] [Accepted: 02/06/2013] [Indexed: 10/27/2022]
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Ginther O, Santos V, Mir R, Beg M. Role of LH in the progesterone increase during the bromocriptine-induced prolactin decrease in heifers. Theriogenology 2012; 78:1969-76. [DOI: 10.1016/j.theriogenology.2012.08.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2012] [Revised: 07/21/2012] [Accepted: 08/01/2012] [Indexed: 11/26/2022]
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Ginther O, Khan F, Hannan M, Beg M. Temporal interrelationships at 15-min intervals among oxytocin, LH, and progesterone during a pulse of a prostaglandin F2α metabolite in heifers. Anim Reprod Sci 2012; 133:63-70. [DOI: 10.1016/j.anireprosci.2012.06.014] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2012] [Revised: 06/14/2012] [Accepted: 06/18/2012] [Indexed: 10/28/2022]
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Pugliesi G, Khan FA, Hannan MA, Beg MA, Carvalho GR, Ginther OJ. Inhibition of prostaglandin biosynthesis during postluteolysis and effects on CL regression, prolactin, and ovulation in heifers. Theriogenology 2012; 78:443-54. [PMID: 22578618 DOI: 10.1016/j.theriogenology.2012.02.024] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2011] [Revised: 02/16/2012] [Accepted: 02/17/2012] [Indexed: 11/18/2022]
Abstract
The beginning of postluteolysis (progesterone, <1 ng mL(-1)) in heifers was targeted by using 8 h after ultrasonic detection of a 25% decrease in CL area (cm2) and was designated Hour 0. Flunixin meglumine (FM; n=10) to inhibit PGF2α secretion or vehicle (n=9) were given intramuscularly at Hours 0, 4, 8, 16, 24, 32, and 40. The dose of FM was 2.5 mg/kg at each treatment. Blood sampling and measurement of the CL and dominant follicle were done every 8 h beginning 14 days postovulation in each group. Blood samples for detection of pulses of PRL and pulses of a metabolite of PGF2α (PGFM) were obtained every hour for 24 h beginning at Hour 0. Pulse concentrations of both PGFM and PRL were lower in the FM group than in the vehicle group. Concentration of PRL was greatest at the peak of a PGFM pulse. Neither CL area (cm2) nor progesterone concentration differed between groups during Hours 0 to 48 (postluteolysis). Ovulation occurred in nine of nine heifers in the vehicle group and in three of 10 heifers in the FM group. The anovulatory follicles in the FM group grew to 36.2±2.9 mm, and the wall became thickened from apparent luteinization. The hypothesis that PGF2α was involved in the continued P4 decrease and structural CL regression during postluteolysis was not supported. However, the hypotheses that pulses of PGFM and PRL were temporally related and that systemic FM treatment induced an anovulatory follicle were supported.
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Affiliation(s)
- G Pugliesi
- Eutheria Foundation, Cross Plains, Wisconsin 53528, USA
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Role of LH in luteolysis and growth of the ovulatory follicle and estradiol regulation of LH secretion in heifers. Theriogenology 2012; 77:1442-52. [DOI: 10.1016/j.theriogenology.2011.11.014] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2011] [Revised: 11/15/2011] [Accepted: 11/19/2011] [Indexed: 11/18/2022]
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Pugliesi G, Beg MA, Carvalho GR, Ginther OJ. Induction of PGFM pulses and luteolysis by sequential estradiol-17β treatments in heifers. Theriogenology 2011; 77:492-506. [PMID: 22119513 DOI: 10.1016/j.theriogenology.2011.08.020] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2011] [Revised: 08/09/2011] [Accepted: 08/10/2011] [Indexed: 10/15/2022]
Abstract
The effects of sequential induction of PGFM pulses by estradiol-17β (E2) on prominence of PGFM pulses and progesterone (P4) concentration were studied in heifers. Three treatments of vehicle (n = 12) or E2 (n = 12) at doses of 0.05 or 0.1 mg were given at 12-h intervals beginning on Day 15 postovulation. Blood samples were collected every 12 h from Days 13-24 and hourly for 12 h after the first and third treatments. On Day 15, all heifers were in preluteolysis and on Day 16 were in preluteolysis in the vehicle-treated heifers (n = 11) and either preluteolysis (n = 4) or luteolysis (n = 8) in the E2-treated heifers. Peak concentration of induced PGFM pulses during preluteolysis on Day 15 was greater (P < 0.04) than for pulses during preluteolysis on Day 16. The interval from ovulation to the beginning of luteolysis was shorter (P < 0.04) in the E2-treated heifers than in the vehicle-treated heifers. An E2-induced PGFM pulse was less prominent (P < 0.008) in heifers in temporal association with a transient resurgence in P4 than in heifers with a progressive P4 decrease. The hypothesis that repeated E2 exposure stimulates increasing prominence of PGFM pulses was not supported. Instead, repeated exposure reduced the prominence of PGFM pulses, in contrast to the stimulation from the first E2 treatment. Reduced prominence of a PGF(2α) pulse during luteolysis can lead to a transient resurgence in P4 concentration.
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Affiliation(s)
- G Pugliesi
- Eutheria Foundation, Cross Plains, Wisconsin, USA
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