| Texto completo | |
| Autor(es): |
Batista, E. O. S.
[1]
;
Cardoso, B. O.
[1]
;
Oliveira, M. L.
[1]
;
Cuadros, F. D. C.
[1]
;
Mello, B. P.
[1]
;
Sponchiado, M.
[1]
;
Monteiro, B. M.
[1]
;
Pugliesi, G.
[1]
;
Binelli, M.
[2]
Número total de Autores: 9
|
| Afiliação do(s) autor(es): | [1] FMVZ USP, Dept Anim Reprodut, Pirassununga, SP - Brazil
[2] Univ Florida, Dept Anim Sci, Gainesville, FL 32611 - USA
Número total de Afiliações: 2
|
| Tipo de documento: | Artigo Científico |
| Fonte: | DOMESTIC ANIMAL ENDOCRINOLOGY; v. 68, p. 126-134, JUL 2019. |
| Citações Web of Science: | 0 |
| Resumo | |
Long-acting injectable progesterone (iP4) supplementation during early diestrus is a strategy to increase conception rates in cow-calf beef operations. However, iP4 treatment causes early functional and structural regression of the corpus luteum (CL) in a proportion of iP4-treated animals, resulting in pregnancy loss. The hypothesis evaluated was that iP4 accelerates downregulation of sex-steroid receptors (PGR, ESR1, ESR2) during early to middiestrus and the upregulation of genes controlling PGF(2)alpha secretion (OXTR, PTGS2, AKR1B1) during late diestrus in the endometrium. Ovulations of cyclic, multiparous Nelore (Bos indicus) cows were synchronized, and cows were divided to receive placebo or 300 mg iP4 3 d postovulation (D3). Growth and vascularization of luteal tissue were evaluated by ultrasonography. Blood samples were collected from 3 d postovulation to 3 d after luteolysis, and P4 plasma concentrations were measured by radioimmunoassay. On days 3, 5, 7, 9, 11, 13, and 16 luminal endometrial samples were taken using a cytologic brush. Transcript abundance was measured by qPCR. Structural luteolysis occurred 3 d earlier in cows receiving iP4 compared to the control group. Analyzing only cows that received iP4, those that presented early luteolysis (ie, <= D16) showed a decrease in CL area and P4 concentration after D5, compared to the control group. Cows that presented early luteolysis showed a reduced abundance of transcripts on D5 for the ESR2 gene and a greater abundance of transcripts for OXTR and ESR1 on D16, compared to cows that did not present early luteolysis. The iP4-induced early luteolysis can be explained by two nonexclusive possibilities: the activation of uterine mechanisms that trigger early secretion of endometrial PGF pulses and the formation of a subfunctional CL that is prone to early regression. (C) 2019 Elsevier Inc. All rights reserved. (AU) | |
| Processo FAPESP: | 15/14814-5 - Controle da luteólise precoce em vacas Bos indicus (Nelore) suplementadas com progesterona injetável de longa ação no início da fase luteínica |
| Beneficiário: | Emiliana de Oliveira Santana Batista |
| Modalidade de apoio: | Bolsas no Brasil - Pós-Doutorado |
| Processo FAPESP: | 11/03226-4 - Assinaturas da receptividade |
| Beneficiário: | Mario Binelli |
| Modalidade de apoio: | Auxílio à Pesquisa - Temático |