Luteal blood flow and progesterone production in mares

Ginther, O.J.; Gastal, E.L.; Gastal, M.O.; Utt, M. D.; Beg, M.A.

doi:10.1016/j.anireprosci.2006.05.018

Cited by 101 publications

(132 citation statements)

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“…The pixel analysis method may be suitable for validation of subjective methods for CL blood flow estimation where the morphology of the structure allows the pixel analysis in a large surface area and not in a restricted area like the follicle wall. Therefore, it is clear that the validation of a subjective method for evaluation of follicle blood flow cannot be deduced from an objective method of blood flow evaluation of CLs, even though high correlations between methods and operators have been previously reported (Ginther et al, 2007c). Thus, it is also possible that a similar methodology to objectively evaluate blood flow for both structures (follicle and CL) could be inaccurate.…”

Section: Discussionmentioning

confidence: 92%

Novel prospects for evaluation of follicle wall blood flow using color-Doppler ultrasonography

et al. 2016

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The goal of this study was to develop an objective method for evaluation of ovarian follicle wall blood flow in cattle. Two subjective methods were used: (I) real-time ultrasound evaluations performed by one operator in the barn and (II) video clip evaluations performed by four operators in the laboratory. The following objective methods evaluated in the laboratory were used for comparison: (I) percentage of follicle wall circumference under blood flow (WUF) and (II) pixel area of color-Doppler signals. Cows (n = 21) were submitted to a synchronization protocol, follicles ≥7 mm were measured, and blood flow was evaluated every 12 h until ovulation using color-Doppler ultrasonography. No difference (P > 0.05) was observed among laboratory operators from day 2 of training onwards. Therefore, an average score of all operators was used for comparisons among different methods. Both subjective and objective methods of evaluation showed an increase (P < 0.0001) in follicle blood flow over time. Higher (P < 0.001) correlations were obtained between WUF and subjective laboratory evaluation than between WUF and pixel area or WUF and subjective barn data. Higher (P < 0.0003) correlation coefficients were observed for WUF than for the pixel area when compared with the barn (r = 0.70 vs. r = 0.42) or laboratory (r = 0.84 vs. r = 0.62) data. Subjective evaluations at the laboratory and barn produced stronger correlations with WUF (P < 0.0008) than with pixel area (P < 0.01). In conclusion, WUF is an effective and reliable method for objective evaluation of follicle wall blood flow in cows.

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Section: Discussionmentioning

confidence: 92%

Novel prospects for evaluation of follicle wall blood flow using color-Doppler ultrasonography

et al. 2016

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“…O ramo uterino da artéria ovariana e o ramo uterino da artéria vaginal também contribuem para a vascularização do útero (Figura 1). Estas três artérias apresentam comunicação entre si e sua extensão varia entre os indivíduos (GINTHER, 2007a). FIGURA 1.…”

Section: Vascularização Do Sistema Reprodutor De éGuasunclassified

Principais Aplicações Da Ultrassonografia Modo Doppler Na Reprodução Em Éguas

Sá¹,

Dutra²,

Nogueira³

et al. 2017

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RESUMOA ultrassonografia modo Doppler tem sido utilizada para acompanhar e avaliar a vascularização do sistema reprodutor de fêmeas equinas. Trata-se de uma tecnologia emergente na Medicina Veterinária que visa análise da vascularização diretamente no local de interesse. Esta ferramenta de análise fornece não apenas informações atuais da estrutura, bem como é capaz de predizer condições futuras, como o potencial de dominância de um folículo ou ainda sua capacidade ovulatória. O modo Power-flow possibilita estudar vasos de pequeno calibre e tortuosos, numerosos no sistema reprodutor de grandes animais. Já o modo espectral é considerado inadequado devido aos sinais de Doppler no endométrio. Para análise do fluxo sanguíneo do corpo lúteo, o modo Doppler consegue detectar alterações durante o ciclo estral e diferenças individuais na vascularização. O exame da estrutura lútea por meio da ultrassonografia modo Doppler de éguas receptoras é uma ferramenta importante, pois auxilia na seleção de animais com perfil sérico de progesterona adequado para o desenvolvimento do embrião e manutenção da gestação. Outra aplicabilidade da ultrassonografia modo Doppler encontrada na literatura consiste na análise de folículos hemorrágicos anovulatórios, que desenvolveram tecido luteal bem vascularizado como indicado através da ecotextura, sinais Doppler colorido e pela produção de progesterona em níveis próximos ao normal. Sendo assim, esta técnica apresenta inúmeras aplicações como método complementar de diagnóstico sobre o sistema reprodutor de éguas. Apesar dos estudos já existentes, novos estudos são necessários visando preencher as lacunas ainda existentes sobre aplicabilidade do modo Doppler.

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“…), just prior to the decline in P secretion during spontaneous luteolysis in the cow [38,39]. A recent report provided additional evidence that during luteolysis, the CL blood flow increases in response to each peak of uterine PGF2α in the heifer [40]. Thus, the increases in luteal blood flow induced by PGF2α are one of the earliest physiological events observed during the luteolytic cascade in the cow.…”

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confidence: 91%

Nitric Oxide and Luteal Blood Flow in the Luteolytic Cascade in the Cow

Shirasuna

2010

Journal of Reproduction and Development

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Abstract. The corpus luteum (CL) of the estrous cycle in the cow is a dynamic organ which has a lifespan of approximately 17-18 days. The main function of the CL is to produce progesterone (P) that requires for achievement and maintenance of pregnancy. If pregnancy does not occur successfully, the CL must regress within a few days to induce the next chance of ovulation. As the CL matures, the steroidogenic cells establish contact with many capillary vessels, consequently the CL is composed of a large number of vascular endothelial cells that can account for up to 50% of all cells. Therefore, blood vessels and blood flow within the CL have an essential role in luteal function. Nitric oxide (NO), a strong vasorelaxant, is now known to play key roles in a variety of physiological process. Indeed, NO has established itself as a polyvalent molecule which plays a decisive role in regulating multiple functions within female reproductive system. In the CL, NO is produced and regulates luteal blood flow, P secretion and apoptosis of luteal cells as well as endothelial cells. This review describes the current investigation for possible roles of NO in the luteolytic cascade within the bovine CL. Key words: Corpus luteum, Luteal blood flow, Luteolysis, Nitric oxide (J. Reprod. Dev. 56: [9][10][11][12][13][14] 2010) he corpus luteum (CL) is a transient organ in the ovary of mammals. The bovine CL rapidly develops within 2-3 days after ovulation, which is accompanied by an active angiogenesis and vascularization from the preovulatory follicle. The main function of the CL is to produce progesterone (P) that requires for achievement and maintenance of pregnancy [1]. If pregnancy does not occur successfully, the CL is only functional for 17-18 days and it must regress within a few days to induce the next chance of ovulation. In ruminants, it is well known that a pulsatile release of prostaglandin F2α (PGF2α) from the uterus on days 17-18 of the estrous cycle is essential to induce regression of the CL [2]. Luteolytic PGF2α induces a drastic decrease in P release from the CL as well as CL volume and blood flow to the CL in the non-pregnant cow [3,4]. Thus, it is easily considered that the bovine CL has well designed mechanisms by which development and regression are effectively controlled.In the cow, the CL is composed of a large number of vascular endothelial cells that can account for up to 50% of all the CL cells [5]. On the other hand, steroidogenic large luteal cells and small luteal cells constitute about 30% of all CL cells [5,6]. The bovine CL also has various cell types such as smooth muscle cells, pericytes, fibrocytes and immune cells, indicating that the CL is a heterogeneous tissue [7,8]. In addition, the CL is constituted by the condensed blood vasculature including large blood vessels and microcapillaries, and the majority of steroidogenic cells are adjacent to one or more capillaries [9]. It is known that a cell-to-cell interaction and these adhesions are essentially important for the CL integrity and physiolog...

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Luteal blood flow and progesterone production in mares

Cited by 101 publications

References 10 publications

Novel prospects for evaluation of follicle wall blood flow using color-Doppler ultrasonography

Novel prospects for evaluation of follicle wall blood flow using color-Doppler ultrasonography

Principais Aplicações Da Ultrassonografia Modo Doppler Na Reprodução Em Éguas

Nitric Oxide and Luteal Blood Flow in the Luteolytic Cascade in the Cow

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