Evaluation of Corpus Luteum Vascularization in Recipient Mares by Using Color Doppler Ultrasound

Marlon de Vasconcelos Azevedo, Natália Matos Souza, Felipe Augusto Boudoux Martins Sales, José Carlos Ferreira-Silva, Maiana Silva Chaves, Joane Isis Travassos Vieira, José Pompeu Santos Filho, Marcos Antonio Lemos Oliveira


Background: Embryo transfer is one of the most commonly used reproductive biotechnique. The success of embryo transfer is also affected by the synchrony of estrus and ovulation between donor and recipient animals. In horse reproduction, ultrasonography has been used, among other purposes, to diagnose early pregnancy. However, only the color Doppler imaging mode makes it possible to evaluate the vascular architecture and the hemodynamic aspects of the vessels in several organs, especially the corpus luteum. The objective of this study was to evaluate, based on the color Doppler ultrasound, the corpus luteum vascularization and function from recipient mares at embryo transfer timing.

Materials, Methods & Results: Mangalarga Machador mares from 5 to 10-year-old and a range of live weights of between 350 to 450 kg were used for this experiment, kept in pasture-based on mombaça grass (Panicum maximum) and were given ad libitum access to water and mineral supplementation. The animals (n = 15) were gynecologically examined and uterine consistency was evaluated by rectal palpation the same operator using an ultrasound system (SonoScape®) with a linear transducer, and operating frequency ranging from 5 to 10 Mhz. The uterine tone was classified between grades 1 and 4 and subjected to ovulation induction. The objective and subjective vascular perfusion of the corpus luteum was evaluated by color Doppler ultrasound on the day of embryo transfer and endometrium. The determination progesterone concentration on the day of the embryo transfer was performed by direct chemiluminescence assay. The arcsine (√P/100) transformation was applied to the percentage data, and the results were expressed as mean (.) ± standard error of the mean (SEM). Further, the assumptions of normality and homoscedasticity were verified, respectively, based on the Shapiro-Wilk and Lilliefors tests. Regarding the parametric and non-parametric variables, were applied, respectively, analysis of variance (ANOVA) followed by Tukey’s test, and the Kruskal-Wallis test followed by Dunn’s test. Pearson’s correlation coefficient was used to evaluate the relationship between the parameters. The statistical program SPSS 16.0 was used to perform the over-mentioned analyses, and a p-value < 0.05 was taken as significant. Corpus luteum vascular perfusion, based on the objective and subjective evaluation methods, and the progesterone concentration were higher in the pregnant mares (P < 0.05). The objective and subjective methods for evaluation of the vascular perfusion in the corpus luteum were positively correlated between themselves as well as to progesterone concentration (P < 0.05). There was no significant difference between the groups considering the uterine tonus evaluation (P > 0.05).

Discussion: Mares that later became pregnant showed a higher concentration of progesterone as an outcome of the higher vascularization in the corpus luteum. It can be supported by both the correlation between the progesterone concentration and the corpus luteum vascular perfusion, as well as by the higher values of the vascular perfusion in pregnant mares. Based on the results, it has been concluded that the color Doppler ultrasound evaluation is an accurate tool to determine the corpus luteum vascularization, whether considering the objective or subjective methods. Also, the vascular perfusion is the most efficient parameter to determine both the corpus luteum function and to predict the ability of the recipient mares to maintain pregnancy.

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Acosta T.J. & Miyamoto A. 2004. Vascular control of ovarian function: Ovulation, corpus luteum formation and regression. Animal Reproduction Science. 82-83: 127-140.

Arruda R.P., Visintin J.A. Fleury J.J., Garcia A.R., Madureira E.H., Celeghini E.C.C. & Neves Neto J.R. 2001. Existem relações entre tamanho e morfoecogenicidade do corpo lúteo detectados pelo ultra-som e os teores de progesterona plasmática em receptoras de embriões eqüinos? Brazilian Journal of Veterinary Research and Animal Science. 38(5): 233-239.

Azevedo M.V., Souza N.M., Ferreira-Silva J.C., Batista I.O., Moura M.T., Oliveira M.A.L., Alvarenga M.A. & Lima P.F. 2015. Induction of multiple ovulations in mares using low doses of GnRH agonist Deslorelin Acetate at 48 hours after luteolysis. Pferdeheilkunde. 31(2): 160-164.

Bollwein H., Mayer R., Weber F. & Stolla R. 2002. Luteal blood flow during the estrous cycle in mares. Theriogenology. 57(8): 2043-2051.

Carnevale E.M., Ramirez R.J., Squires E.L., Alvarenga M.A., Vanderwall D.K. & McCue P.M. 2000. Factors affecting pregnancy rates and early embryonic death after equine embryo transfer. Theriogenology. 54(6): 965-979.

Curran S. & Ginther O.J. 1995. M-mode ultrasonic assessment of equine fetal heart rate. Theriogenology. 44(5): 609-617.

Dharmarajan A.M., Bruce N.W. & Meyer G.T. 1985. Quantitative ultrastructural characteristics relating to transport between luteal cell cytoplasm and blood in the corpus luteum of the pregnant rat. American Journal of Anatomy. 172(1): 87-99.

Ferreira J.C., Ignácio F.S. & Meira C. 2011. Doppler ultrasonography principles and methods of evaluation of the reproductive tract in mares. Acta Scientiae Veterinariae. 39(Supl 1): s105-s111.

Ferreira-Silva J.C., Sales F.A.B.M., Nascimento P.S., Moura M.T., Freitas-Neto L.M., Rocha J.M., Ferreira H.N. & Oliveira M.A.L. 2019. Evaluation of embryo collection and transfer days on pregnancy rate of mangalarga marchador mares during the breeding season. Revista Colombiana de Ciências Pecuárias. 32(3): 214-220.

Ferreira J.C., Novaes Filho L.F., Boakari Y.L., Canesin H.S., Thompson D.L., Lima F.S. & Meira C. 2018. Hemodynamics of the corpus luteum in mares during experimentally impaired luteogenesis and partial luteolysis. Theriogenology. 107: 78-84.

Ginther O.J., Gastal E.L., Gastal M.O., Utt M.D. & Beg M.A. 2007. Luteal blood flow and progesterone production in mares. Animal Reproduction Science. 99(1-2): 213-220.

Ginther O.J. & Utt M.D. 2004. Doppler ultrasound in equine reproduction: Principles, techniques, and potential. Journal of Equine Veterinary Science. 24(12): 516-526.

Ishak G.M., Bashir S.T., Gastal M.O. & Gastal E.L. 2017. Pre-ovulatory follicle affects corpus luteum diameter, blood flow, and progesterone production in mares. Animal Reproduction Science. 187: 1-12.

Iuliano M.F., Squires E.L. & Cook V.M. 1985. Effect of age of equine embryos and method of transfer on pregnancy rate. Journal of Animal Science. 60(1): 258-263.

Lüttgenau J., Ulbrich S.E., Beindorff N., Honnens A., Herzog K. & Bollwein H. 2011. Plasma progesterone concentrations in the mid-luteal phase are dependent on luteal size, but independent of luteal blood flow and gene expression in lactating dairy cows. Animal Reproduction Science. 125(1-4): 20-29.

McCue P.M., Vanderwall D.K., Keith S.L. & Squires E.L. 1999. Equine embryo transfer: Influence of endogenous progesterone concentration in recipients on pregnancy outcome. Theriogenology. 51(1):267.

Mortensen C.J., Choi Y.H., Hinrichs K., Ing N.H., Kraemer D.C., Vogelsang S.G. & Vogelsang M.M. 2009. Embryo recovery from exercised mares. Animal Reproduction Science. 110(3-4): 237-244.

Nagao J.F., Neves Neto J.R., Papa F.O., Alvarenga M.A., Freitas-Dell’Aqua C.P. & Dell’Aqua J.A. 2012. Induction of double ovulation in mares using deslorelin acetate. Animal Reproduction Science. 136(1-2): 69-73.

Niswender G.D., Juengel J.L., Silva P.J., Rollyson M.K. & McIntush E.W. 2000. Mechanisms controlling the function and life span of the corpus luteum. Physiological Reviews. 80(1): 1-29.

Oliveira Neto I.V., Canisso I.F., Segabinazzi L.G., Dell’Aqua C.P.F., Alvarenga M.A., Papa F.O. & Dell’Aqua J.A. 2018. Synchronization of cyclic and acyclic embryo recipient mares with donor mares. Animal Reproduction Science. 190: 1-9.

Romano R.M., Ferreira J.C., Canesin H.S., Boakari Y.L., Ignácio F.S., Novaes Filho L.F., Thompson D.L. & Meira C. 2015. Characterization of Luteal Blood Flow and Secretion of Progesterone in Mares Treated with Human Chorionic Gonadotropin for Ovulation Induction or During Early Diestrus. Journal of Equine Veterinary Science. 35(7): 591-597.

Veronesi M.C., Battocchio M., Marinelli L., Faustini M., Kindahl H. & Cairoli F. 2002. Correlations among body temperature, plasma progesterone, cortisol and prostaglandin F2α of the periparturient bitch. Journal of Veterinary Medicine Series A: Physiology Pathology Clinical Medicine. 49(5): 264-268.

Wilsher S. & Allen W.R. 2009. Uterine influences on embryogenesis and early placentation in the horse revealed by transfer of day 10 embryos to day 3 recipient mares. Reproduction. 137(3): 583-593.

Wilsher S., Clutton-Brock A. & Allen W.R. 2010. Successful transfer of day 10 horse embryos: Influence of donor-recipient asynchrony on embryo development. Reproduction. 139: 575-585.

DOI: https://doi.org/10.22456/1679-9216.110960

Copyright (c) 2021 Marlon Azevedo, Natália Souza, Felipe Sales, José Ferreira-Silva, Maiana Chaves, Joane Vieira, José Santos filho, Marcos Oliveira

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