Ultrasonography of the conceptus development from days 15 to 60 of pregnancy in non-cyclic recipient mares

Silva, Elisa Sant'Anna Monteiro da; Pantoja, José Carlos de Figueiredo; Puoli, José Nicolau Próspero; Meira, Cezinande de

doi:10.1590/0103-8478cr20140517

Cited by 8 publications

(9 citation statements)

References 14 publications

(20 reference statements)

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“…In the past few years, various doses of E2 has been given to intact non-cyclic recipient mares and after observation of uterine edema, long acting progesterone (LA P4) [6,7] or altrenogest [2,9] has been administered three to eight days prior to embryo transfer. Recently, it was demonstrated that the administration of a single dose of 2.5 mg of estradiol benzoate to anestrous mares produces similar estrogen concentration to that found in cyclic mares [10].…”

Section: Introductionmentioning

confidence: 99%

“…The protein immunostaining and changes in abundance of transcripts for ER and PR have not yet been described in noncyclic mares treated with hormonal protocols to become embryo recipients. In previous studies [2,9], we could demonstrate that the administration of 2.5 mg of estradiol benzoate (EB) followed by progestin administration was able to establish and maintain pregnancy in either anestrous or transitional mares. Therefore, to test the hypothesis that the administration of a single dose of 2.5 mg of EB followed by 1500 mg of LA P4 in anestrous and transitional mares promote similar uterine edema, tone and molecular dynamics to those observed in non-treated cyclic mares, we described and compared protein immunolocalization and changes in relative abundance of transcripts for ERa, ERb and PR, as well as the uterine characteristics and estrogen and P4 profile during the hormonal treatment.…”

Section: Introductionmentioning

confidence: 99%

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Administration of 2.5 mg of estradiol followed by 1,500 mg of progesterone to anovulatory mares promote similar uterine morphology, hormone concentrations and molecular dynamics to those observed in cyclic mares

et al. 2017

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To test the hypothesis that the administration of 2.5 mg of estradiol benzoate (EB) followed by 1500 mg of long acting progesterone (LA P4) causes similar uterine changes and molecular dynamics in anovulatory mares to those observed in cyclic ones, we evaluated the changes of estrogen (ERα and ERβ) and progesterone receptors (PR) in anestrous, transitional and cyclic mares by RT-qPCR and immunohistochemistry. In addition, we evaluated uterine edema, tonus and estrogens and progesterone plasma profile. Endometrial biopsies were taken from anestrous and transitional mares immediately before EB injection, 48 h after EB administration and five days after LA P4 was given. In cyclic mares, biopsies were collected at estrus and at five days after ovulation. Similar estrogen peaks were achieved after the injection of the single EB dose between treated and cyclic groups, as well as maximum uterine edema. Uterine tone was increased to diestrus levels after administration of 1500 mg of LA P4. Changes in relative abundance of transcripts for PR, ERα and ERβ when progesterone stimulated endometrium was compared to estrogen stimulated endometrium were similar between cyclic and non-cyclic treated mares. However, apparent decreased PR in the endometrial glandular epithelium was not observed in non-cyclic mares five days after LA P4 administration as observed at five days after ovulation in cyclic mares. The protocol produced similar endometrial edema, uterine tonus and changes in relative abundance of PR, ERα and ERβ transcripts to those observed in cyclic mares during late estrus and early diestrus, as well as similar estradiol and estrogen conjugate plasma concentrations.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Administration of 2.5 mg of estradiol followed by 1,500 mg of progesterone to anovulatory mares promote similar uterine morphology, hormone concentrations and molecular dynamics to those observed in cyclic mares

et al. 2017

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“…Currently, noncyclic recipient mares often receive estradiol benzoate (EB) [2,7,8], an ester of the natural estrogen 17bestradiol (E2) with an approximate half-life of 3 days [9]. After the observation of endometrial edema, long-acting progesterone (LA P4; half-life of 7 days) is administered 3 to 8 days before ET [3,10], or altrenogest is given during 4 to 6 days before transfer [2,11], to achieve an appropriate progesterone concentration (!2.5 ng/mL) [6] at the time of ET. These hormones (natural or synthetic) induce similar uterine changes to those which occur in cyclic mares [12], such as endometrial edema caused by estradiol followed by increased uterine tone and stimulus to histotrophic secretion as a result of exogenous progestin treatment [13].…”

Section: Introductionmentioning

confidence: 99%

“…Although protocols for exogenous P4 have already been described regarding suitable P4 concentrations for pregnancy maintenance [14], EB administration is empirical with different reports of dose and administration frequencies for preparing noncyclic recipient mares such as a single dose of 2.5 mg [2,11] and decreasing doses of 5 [15] or 10 mg [7,8].…”

Section: Introductionmentioning

confidence: 99%

Comparison of different regimens of estradiol benzoate treatments followed by long-acting progesterone to prepare noncycling mares as embryo recipients

et al. 2016

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The present study evaluated the influence of different regimens of estradiol benzoate (EB) treatments followed by a single dose of long-acting progesterone (LA P4) on plasma estrogen and P4 concentrations in noncyclic mares prepared as embryo recipients. Twenty-one anestrous mares were distributed into three groups (n = 7 mares per group), according to the EB dose received (single dose of 2.5 mg, total of 5 mg in decreasing doses, and total of 10 mg in decreasing doses), which was followed by a single administration of 1500 mg of LA P4 in all groups. Mares were reevaluated during the ovulatory phase and seven of them became part of the cyclic nontreated control group. Ultrasonography was performed to monitor endometrial edema, and blood samples were collected to measure estradiol (E2), estrogen conjugate (EC), and P4 by RIA. Maximum uterine edema was achieved 24 hours after administration of EB in all treated groups. Maximum E2 concentrations were observed 24 hours after the first EB injection in treated groups and there were no differences (P > 0.05) among treatments. Maximum EC concentration was observed 24 hours after the single EB injection in the 2.5-mg group, whereas in the 5- and 10-mg groups EC peaks were observed 48 hours after the first EB administration. Maximum P4 concentrations were detected 24 hours after LA P4 injection, although higher P4 concentrations were observed in the group treated with 2.5 mg of EB than in that treated with 10 mg of EB (P < 0.05). Because P4 concentrations were reduced after administration of high doses of EB, we also measured 17α-hydroxyprogesterone (17-OH-P) to test the hypothesis that high concentrations of EB would accelerate the conversion of P4 to 17-OH-P. However, 17-OH-P concentrations paralleled P4 profile in all groups, irrespective of EB doses. In summary, the three EB treatment regimens induced similar E2 peaks, although the observation of EC peaks 24 hours after E2 peaks in the 5- and 10-mg groups indicate that an excess of E2 was given, which was converted into EC to be inactivated. Administration of 10 mg of EB reduced P4 concentrations 24 hours after LA P4 was given. We demonstrated that the mechanism by which this reduction occurred was not by an increase in P4 metabolism to 17α-OH-P. In conclusion, the use of 2.5 mg of EB followed by 1500 mg of LA P4 appears to be a more appropriate regimen to treat noncyclic mares, although additional studies are needed to verify embryo survival with this treatment dose.

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“…Transrectal palpation was conducted on days 21-30 after mating to palpate the presence of the CL on the ovaries and to determine the position of CL in the left or right ovary. Pregnancy diagnosis through transrectal palpation was conducted on 40-45 days post-mating and confirmed using a Doppler ultrasound [9,11] BT-200 scanner (Bistos, South Korea).…”

Section: Treatment Estrus Detection Mating and Pregnancy Diagnosismentioning

confidence: 99%

Fertility restoration of racing mare with persistent corpus luteum

et al. 2021

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Background and Aim: Persistent corpus luteum (PCL) causes anestrus in mares. This study aimed to determine the effect of intrauterine prostaglandin F2α (PGF2α) treatment on PCL of racing mares to restore fertility. Materials and Methods: Twelve racing mares suspected with PCL were diagnosed using transrectal palpation and confirmed by serum progesterone (P4) concentration measurement. PGF2α was infused intrauterine, followed by serum collection at 24, 48, and 72 h after. Estrous symptoms were monitored, and mating was conducted on day 3 of estrus with an earlier injection of 8.4 μg gonadotropin-releasing hormone twice a day. Transrectal palpation was performed on days 21-30 to observe the corpus luteum. Pregnancy diagnosis was performed rectally on 40-45 days post-mating and confirmed using Doppler ultrasound scanning. Results: Eleven of the 12 mares had PCL. There was a dramatic reduction in the P4 concentration following PGF2α treatment of mares with PCL. All mares exhibited estrus 2.6±0.55 days post-treatment with a P4 concentration of 0.12±0.12 ng/mL. Rectal palpation and P4 concentration on 21-30 days after estrous onset showed that all mares were ovulating. The evaluation of P4 concentration on days 40-45 post-mating showed that all mares were still in the luteal phase. However, the pregnancy rate was only 54.5% based on rectal palpation and Doppler ultrasound scanning. Conclusion: Treatment of PCL in racing mares with an intrauterine infusion of PGF2α restored the estrous cycle and induced ovulation and pregnancy.

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Ultrasonography of the conceptus development from days 15 to 60 of pregnancy in non-cyclic recipient mares

Cited by 8 publications

References 14 publications

Administration of 2.5 mg of estradiol followed by 1,500 mg of progesterone to anovulatory mares promote similar uterine morphology, hormone concentrations and molecular dynamics to those observed in cyclic mares

Administration of 2.5 mg of estradiol followed by 1,500 mg of progesterone to anovulatory mares promote similar uterine morphology, hormone concentrations and molecular dynamics to those observed in cyclic mares

Comparison of different regimens of estradiol benzoate treatments followed by long-acting progesterone to prepare noncycling mares as embryo recipients

Fertility restoration of racing mare with persistent corpus luteum

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