An in vitro investigation of the actions of reproductive hormones on the cervix of the ewe in the follicular stage: The effects of 17β-estradiol, oxytocin, FSH, and arachidonic acid on the cervical pathway for the synthesis of prostaglandin E2

Falchi, Laura; Scaramuzzi, R. J.

doi:10.1016/j.theriogenology.2014.12.003

Cited by 14 publications

(15 citation statements)

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“…Oestrogen and PGE 2 receptors are more present in the medial and caudal zone, whereas OT receptors are more common in the cranial zone (Rodríguez‐Piñón et al., ). During the periovulatory period, the cervix of the ewe is slightly dilated due to the effect of hormones such as PGE 2 and OT in response to the increase in oestrogen (Falchi & Scaramuzzi, ). Cervical penetration is improved in the reproductive season and is related to an oestrogen ‘dilator’ effect in consecutive oestrus (Windsor, ).…”

Section: Transcervical Intrauterine Insemination: a Challenge Mid‐waymentioning

confidence: 99%

Current challenges in sheep artificial insemination: A particular insight

Álvarez

Anel-López

Boixo

et al. 2019

Reprod Domestic Animals

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Ovine artificial insemination (OAI) is not commonly performed because of specific problems related to semen application techniques, leading to highly variable results.The ideal methodology (frozen-thawed semen/vaginal route) is unfeasible under field conditions due to the cervix morphology of the ewe, which prevents the process of intrauterine insemination necessary to obtain acceptable results. Currently, OAI commercial programmes use superficial cervical insemination, CAI (vaginal), with chilled semen (15°C) and intrauterine insemination, LAI (laparoscopic), with frozen-thawed semen. The ability to improve upon these contrasting techniques may be derived from examining certain poorly studied factors such as insemination time, productive state of females and alternatives of seminal preservation, some of which we reviewed in this work. This interim solution will remain in use until AI by the vaginal route with frozen-thawed semen is developed, but it poses new challenges in optimizing the freezing of the sperm and adapting the cervical (CAI) and/or transcervical intrauterine AI (TCAI). In this review, we address the current problems and evaluate their methodological (mechanical) and chemical (dilation) alternatives. Currently, TCAI is a methodologically complex technique with poor fertility results, so further studies are needed to improve the logistics of this procedure and the results of its application. K E Y W O R D SAI, cervix, cryopreservation, ovine, sperm, transcervical | 33 ALVAREZ Et AL.

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Section: Transcervical Intrauterine Insemination: a Challenge Mid‐waymentioning

confidence: 99%

Current challenges in sheep artificial insemination: A particular insight

Álvarez

Anel-López

Boixo

et al. 2019

Reprod Domestic Animals

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“…The role of oxytocin (OT) in triggering uterine contractility and cervical dilation during parturition (Khalifa, Sayre, & Lewis, ) as well as in stimulating endometrial PGF 2α secretion to promote luteolysis in ruminants (Falchi & Scaramuzzi, ) is commonly known. In cows (Fuchs, Ivell, Fields, Chang, & Fields, ) and ewes (Ayad, Leung, Parkinson, & Wathes, ), elevated oestradiol concentrations during the follicular phase of the oestrous cycle lead to an increase in oxytocin receptors (OTR) concentration in the epithelial cells of the cervical mucosa layer.…”

Section: Introductionmentioning

confidence: 99%

“…In cows (Fuchs, Ivell, Fields, Chang, & Fields, ) and ewes (Ayad, Leung, Parkinson, & Wathes, ), elevated oestradiol concentrations during the follicular phase of the oestrous cycle lead to an increase in oxytocin receptors (OTR) concentration in the epithelial cells of the cervical mucosa layer. Systemic and luteal OT binding to these receptors promotes the release of arachidonic acid from the phospholipid membranes of the endometrial tissue, which is then converted by cyclooxygenase 2 into prostaglandin H, the precursor for PGE 2 synthesis (Falchi & Scaramuzzi, ). PGE 2 acts on the adjacent connective tissue and smooth muscle cells to induce cervical dilation and facilitate sperm transport through the cervical canal during the periconceptional period (Fuchs, Graddy, Kowalski, & Fields, ).…”

Section: Introductionmentioning

confidence: 99%

Comparison of the intravenous and intravaginal route of oxytocin administration for cervical dilation protocol and non‐surgical embryo recovery in oestrous‐induced Santa Inês ewes

Prellwitz

Zambrini

Guimarães

et al. 2019

Reprod Domestic Animals

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This study compared the effects of intravaginal and intravenous routes of oxytocin (OT) administration in 46 oestrous-induced Santa Inês ewes (6-day treatment with progestin-releasing intravaginal sponges and a single injection of 200 IU of eCG at the time of sponge removal) that underwent transcervical embryo recovery 6-7 days after oestrous onset and mating. All ewes received 37.5 μg of d-cloprostenol via latero-vulvar route, and 1 mg of oestradiol benzoate i.m. 16 hr before and 50 IU of OT 20 min before non-surgical embryo recovery (NSER), with OT being administered intravenously (n = 21) or intravaginally (n = 21). An overall oestrous response was 95.6% (44/46), and adequate cervical retraction could be accomplished in 78.6% (33/42) of ewes. The percentage of successful NSER procedures was 57% (24/42) or 72.7% (24/33) of animals with sufficient cervical retraction. The duration of NSER procedure averaged 28 min (range: 17-40 min) and ~96% of flushing fluid could be recovered (range: 85%-100%). Out of 18 ewes that could not undergo NSER, 12 (66.6%) presented various anatomical barriers, whilst the other 33.4% did not present these barriers and still could not be traversed. Excluding the ewes with those anatomical features, the overall success rate of NSER was 80% (24/30). The route of OT administration had no effect on NSER efficiency or the ease with which transcervical embryo flushing was performed. Both routes of OT administration can be used for cervical dilation protocol. Discarding ewes with anatomical features precluding cervical penetration is highly recommended to increase the efficacy of NSER in sheep. K E Y W O R D S cervical relaxation, sheep, transcervical embryo collection, uterine flushing | 1231 PRELLWITZ ET aL. How to cite this article: Prellwitz L, Zambrini FN, Guimarães JD, et al. Comparison of the intravenous and intravaginal route of oxytocin administration for cervical dilation protocol and non-surgical embryo recovery in oestrousinduced Santa Inês ewes. Reprod Dom

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“…Non-pregnant animals show a natural degree of cervical dilation during the follicular phase of the estrus cycle (Kershaw-Young et al, 2009). Studies propose that a sequence of events trigger this relaxation, starting with the follicular development induced by FSH which stimulates a periovolatory increase of 17-ß-estradiol and consequently a higher expression of oxytocin receptors (Falchi and Scaramuzzi, 2015). Some studies with oxytocin and estradiol increased cervical transposition rate in ewes Masoudi et al, 2012).…”

Section: Introductionmentioning

confidence: 99%

Cervical relaxation for non-surgical uterus access in Santa Inês ewes

Leite

Fonseca

Fernandes

et al. 2018

Arq. Bras. Med. Vet. Zootec.

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The present study was composed by two experiments aiming to develop a cervical dilation technique for non-surgical access to Santa Inês ewe's uterus. In Experiment 1, thirty ewes underwent four epidural treatments. The three experimental treatments used 2.0mg/kg ketamine. The group receiving this drug alone was denominated KG, whereas other group had ketamine associated with 0.1mg/kg morphine (KM) and KX a third group had ketamine associated with 0.05mg/kg xylazine (KX). Control treatment was 1mL/7.5kg saline solution epidurally (CON). Cervical dilation was evaluated in both experiments by attempting to pass a metal rod through the cervix. In Experiment 2, three different hormonal protocols for cervical dilation were tested in thirty ewes. Epidural anesthesia with 2.0mg/kg ketamine was the control treatment (KG) and was combined with hormonal treatments: Misoprostol (MI); Oxytocin + Estradiol (OE); Misoprostol + Oxytocin + Estradiol (MOE). In Experiment 1 transposition rate was not different among groups. In Experiment 2, OE presented the highest rate (90%) while MOE presented 86.2%, MI 68.9% and CON 62.1%. The study developed a pharmacological protocol that increased cervical transposition making the non-surgical access to the uterus feasible in Santa Inês ewes. RESUMOO presente estudo teve como objetivo desenvolver uma técnica para acesso não cirúrgico ao útero de ovelhas Santa Inês e foi realizado em duas etapas. No experimento 1, 30 ovelhas foram submetidas a quatro tratamentos epidurais. Os três tratamentos teste usaram 2,0mg/kg de cetamina. O grupo que recebeu apenas cetamina foi denominado KG, enquanto no segundo grupo a cetamina foi combinada com morfina (0,1mg/kg -KM) e um terceiro grupo recebeu cetamina associada com xilazina 0,05mg/kg -KX). No grupo controle (CON), usou-se solução salina (1mL/7,5kg de peso). A dilatação cervical foi avaliada em ambos os experimentos pela tentativa de transposição cervical com uma haste metálica. No experimento 2, três protocolos hormonais de dilatação cervical foram testados em 30 ovelhas. Anestesia epidural com 2,0mg/kg de cetamina foi o tratamento controle (CON), combinada com tratamentos hormonais nos grupos: misoprostol (MI); ocitocina + estradiol (OE); misoprostol + ocitocina + estradiol (MOE). No experimento 1, a taxa de transposição não variou entre os grupos. No experimento 2, OE teve a maior taxa (90%), enquanto MOE apresentou 86,2%, MI i 68,9% e CON 62,1%. O estudo desenvolveu um protocolo farmacológico que aumentou a taxa de transposição cervical, tornando o acesso uterino não cirúrgico viável em ovelhas Santa Inês.

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An in vitro investigation of the actions of reproductive hormones on the cervix of the ewe in the follicular stage: The effects of 17β-estradiol, oxytocin, FSH, and arachidonic acid on the cervical pathway for the synthesis of prostaglandin E2

Cited by 14 publications

References 50 publications

Current challenges in sheep artificial insemination: A particular insight

Current challenges in sheep artificial insemination: A particular insight

Comparison of the intravenous and intravaginal route of oxytocin administration for cervical dilation protocol and non‐surgical embryo recovery in oestrous‐induced Santa Inês ewes

Cervical relaxation for non-surgical uterus access in Santa Inês ewes

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