The effects of perphenazine and bromocriptine on follicular dynamics and endocrine profiles in anestrous pony mares

Bennett-Wimbush, K.; Loch, Wayne Eugene; Plata-Madrid, H.; Evans, Tim

doi:10.1016/s0093-691x(98)00021-1

Cited by 33 publications

(16 citation statements)

References 36 publications

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“…Twice daily bromocriptine injections to mares in vernal transition reduced plasma prolactin concentrations and seemed to delay the growth of preovulatory follicles [46]; however, no effect was observed for date of first ovulation. In a study with similar results (no effect on first ovulation), Oberhaus et al [53] used a long-acting dopaminergic compound, cabergoline, in every-10-day injections in a slow-release vehicle to suppress prolactin concentrations in mares starting on February 4.…”

Section: Dopaminergic and Antidopaminergic Compoundsmentioning

confidence: 88%

“…Johnson and Becker [38] were the first to confirm that, in fact, administration of bromocriptine, a dopamine agonist, reduced serum prolactin concentrations in horses in May, when concentrations were high, and that two dopaminergic antagonists, metoclopramide and sulpiride, each alone stimulated an immediate response in serum prolactin concentrations. Subsequent reports of the use of perphenazine [45,46] and domperidone [47] in mares confirmed their stimulatory effects on prolactin secretion in the short term. Repeated daily injections of sulpiride in vegetable shortening (to slow its release) to stallions for 14 days in winter [40] increased plasma prolactin concentrations in daily blood more than sixfold, to levels comparable to those normally found in stallions in summer.…”

Section: Dopaminergic and Antidopaminergic Compoundsmentioning

confidence: 90%

See 1 more Smart Citation

Prolactin in the Horse: Historical Perspective, Actions and Reactions, and Its Role in Reproduction

Thompson

Oberhaus

2015

Journal of Equine Veterinary Science

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Section: Dopaminergic and Antidopaminergic Compoundsmentioning

confidence: 88%

Section: Dopaminergic and Antidopaminergic Compoundsmentioning

confidence: 90%

Prolactin in the Horse: Historical Perspective, Actions and Reactions, and Its Role in Reproduction

Thompson

Oberhaus

2015

Journal of Equine Veterinary Science

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“…In heifers, LH concentrations increased during the bromocriptine-induced decrease in PRL ). In the current study and reported studies (BENNETT-WIMBUSH et al, 1998;BRENDENMUEHL;CROSS, 2000) in mares, an effect of bromocriptine treatment on LH and FSH was not detected.…”

Section: Discussioncontrasting

confidence: 46%

“…This was shown by the reduced group effect that considered all values in a pulse, by lower concentrations at the nadirs and pulse peak, and by fewer CV-identified pulses during September in the Bc group. Bromocriptine treatment has been given previously to mares -WIMBUSH et al, 1998;FITZGERALD;DAVISON;MCMANUS, 2000), but the absence of an effect on PGFM concentrations had not been reported previously.…”

Section: Discussionmentioning

confidence: 94%

Dinâmica hormonal durante o processo luteolítico nas espécies equina e bovina; com ênfase sobre o papel da prolactina

Pinaffi¹,

Silva²

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Primeiramente gostaria de agradecer a todos que me apoiaram durante o caminho percorrido desde o ingresso no curso de medicina veterinária até o momento. Em especial, meus pais Sônia e Wagner, pelo apoio e suporte em minhas decisões e companheirismo em todas as atividades, e minhas irmãs Flávia e Juliana, por sempre estarem presentes durante toda minha formação.Durante minha formação tive a sorte de ter oportunidades únicas ao lado de professores como a Profa. Dra. Eneiva Carla Carvalho Celeghini e Prof. Dr. Rubens Paes de Arruda, os quais contribuiram com o início de minha jornada pelas pesquisas. Foram grandes educadores, tanto pelos ensinamentos científicos como pela abertuda de oportunidades que alavancaram minha carreira.Nada disso seria possível sem as mãos do Prof. Dr. Luciano Andrade Silva, sempre me guiando ao conhecimento de ponta. Agradeço imensamente o convite em me orientar e me enviar à fonte de grande parte de seu conhecimento, ao laboratório do Dr. O. J. Ginther. As conquistas foram monumentais, e muito ainda está por vir.Como pessoa mais importante para a realização de todos estes trabalhos, devo um grande agradecimento ao Dr. O. J. Ginther. Seja pela recepção, atenção, paciência e devoção às pesquisas. Defendo que o Dr. Ginther é um ser humano a ser eternizado. Posso afirmar que cada parágrafo dessa dissertação teve o toque não de apenas um pesquisador apaixonado pela escrita, mas sim de um artista.Especialista nem análises hormonais, grande conhecedor de estatística e importante chefe de laboratório, devo um muitíssimo obrigado ao Dr. M. A. Beg. Sempre caminhando ao lado do Dr. Ginther, é responsável por todas as análises de dados prévias à redação dos trabalhos. Pude vivenciar e aprender muito com esses grandes cientistas e percebi que o conhecimento é ilimitado quando permanecemos em sua procura.Não posso esquecer-me de agradecer toda a equipe da Eutheria Foundation em Cross Plains, WI, USA; fazenda em que fiquei por um ano em trabalhos árduos rodeados de muitas descobertas. Tenho que agradecer primeiramente ao Guilherme Pugliesi, que fez parte do início de minhas pesquisas, seja no delineamento de experimentos, estatística e manejo com os animais, quanto pela grande amizade no período em que permaneceu na Eutheria Foundation. Agradeco aos demais colegas de trabalho e amigos que fizeram parte de minhas pesquisas como: Firdous Khan, Luis Felipe Duarte, Andrew Pritzl, Maria Belén, Vanda Santos, Hannan, Raies Mir, Hemanta Shrestha e Maria Hoffman.Por fim, devo um imenso agradecimento a meus familiares, os quais sempre me apoiaram e, mesmo distantes no período em que fiquei no exterior, mantiveram contato por conversas online naqueles almoços de familia num domingo. Meus pais, avós, tios, primos e irmãs sempre estarão acima de todas as conquistas. Por fim devo um especial agradecimento a todos amigos e amigas que estiveram comigo durante o mestrado, tanto aqui no Brasil quanto nos EUA. Evito citar nomes, pois são inúmeros para poucas páginas. Apesar de alguns estarem distantes no momento, sei qu...

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“…The mechanisms that may lead to this phenomenon, thus far, remain unknown. In anestrous mares, current evidence suggests that the absence of reproductive activity reflects a suppression of gonadotropin secretion due to inhibition of GnRH secretion resulting from increased dopaminergic [4][5][6] and opioidergic activity [7][8][9][10]. Thus, the continuation of estrous cycles during the nonbreeding season may result from a reduced inhibitory action (i.e., reduced ''tone'') by one or both of the aforementioned neural systems.…”

Section: Introductionmentioning

confidence: 99%

Gonadotropin Response to Naloxone in the Mare: Effect of Time of Year and Reproductive Status1

Davison¹,

McManus²,

Fitzgerald³

1998

Biology of Reproduction

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In the mare, endogenous opioids have been implicated in the suppression of gonadotropin secretion during seasonal anestrus (AN). The present study tested whether continuation of reproductive activity during the nonbreeding season (NBS) reflects the absence of a seasonal shift in opioid tone compared to what occurs in AN mares. During the NBS, 11 AN and 8 luteal-phase mares received 0.1, 0.05, 0. 025 mg/kg naloxone (NAL) or vehicle on alternate days. Whereas cycling mares responded to all dosages of NAL, AN mares responded only to the higher dosages for FSH, and LH failed to increase at any dosage employed. During the breeding season (BS), the response to these dosages of NAL was reevaluated in 12 mares in the luteal phase of a synchronized estrous cycle. Although there was no difference between cycling mares during the breeding and nonbreeding seasons in FSH response, those mares that had cycled during the NBS showed a greater LH response to 0.05 mg/kg NAL than mares during the BS. From these data, we conclude that opioid tone is lower during the BS than during AN and that this shift in inhibitory tone does not occur in mares that cycle during the NBS. Thus, reduced opioid tone may play a role in the mechanisms controlling the nonseasonal exhibition of estrous cycles in the mare.

show abstract

The effects of perphenazine and bromocriptine on follicular dynamics and endocrine profiles in anestrous pony mares

Cited by 33 publications

References 36 publications

Prolactin in the Horse: Historical Perspective, Actions and Reactions, and Its Role in Reproduction

Prolactin in the Horse: Historical Perspective, Actions and Reactions, and Its Role in Reproduction

Dinâmica hormonal durante o processo luteolítico nas espécies equina e bovina; com ênfase sobre o papel da prolactina

Gonadotropin Response to Naloxone in the Mare: Effect of Time of Year and Reproductive Status1

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