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Effect of the periovulatory endocrine milieu on the uterine environment quality in beef cows: regulation on the polyamines metabolism, oxidative stress and cellular proliferation

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Roney dos Santos Ramos
Total Authors: 1
Document type: Doctoral Thesis
Press: Pirassununga.
Institution: Universidade de São Paulo (USP). Faculdade de Medicina Veterinária e Zootecnia (FMVZ/SBD)
Defense date:
Examining board members:
Mario Binelli; Marcos Roberto Chiaratti; Paulo Bayard Dias Gonçalves; Marcella Pécora Milazzotto; Marcilio Nichi
Advisor: Mario Binelli

This work aimed to compare the effects of the different periovulatory endocrine milieu on the several molecular pathways: as cellular proliferation, polyamine metabolism and redox environment of the bovine uterus during the early diestrus. For this, we controlled pharmacologically the follicular growth to induce the ovulation of larger follicle (Large Follicle-Large Corpus lutem group LF-LCL) or smaller follicle (Small follicle-Small Corpus luteum group SF-SCL). Thirty multiparous Nelore cows were synchronized. Fifteen cows were assigned for each group. On the LF-LCL, the cows received a dose of prostaglandin F2&#945; (PGF), a progesterone device and an estradiol benzoate on D10. On the time of progesterone device was withdraw (between D1.75 e D2.5) all the animals received a dose of PGF. The ovulation was induced with buserelin acetate (D0). The unique difference between the groups was that animals of SF-SCL did not received a dose of PGF on D10 and the progesterone device withdraw was between D1.25 e o D1.5. On D7 a subset of animals was slaughtered and the endometrial and uterine washings samples were collected for laboratorial analyses. On D0 the animals of LF-LCL had a 1.2 times larger follicles and 2.3 times higher levels of estradiol than animals of SF-SCL. Firstly, an endometrial transcriptome analyses was realized and suggested that several cellular processes as proliferation, metabolic processes and oxi-reduction processes were affected by experimental model. To evaluate the proliferative and/or apoptotic condition, endometrial immunohistochemistry analyses were realized (ki-67, proliferation marker and caspase 3 activated, apoptose marker). The number of Ki-67 positive cells in the luminal epithelium was 4.1 times higher on SF-SCL. However, there was no difference in caspase 3 activated analyses. On the glandular epithelium both ki-67 (1.4) and caspase 3 activated (2.6) were increased on LF-LCL. About polyamine synthesis pathway there was no difference in polyamines levels and gene and protein expression of synthesis enzymes between the groups. In other hand, it was detected a strong association between SAT1 gene expression and ODC1 gene expression (r2: 0.73; P<0.01) and also between AZIN1 and AMD1 gene expression (r2: 0.61; P<0.01). On the redox environment analysis there was no difference between the groups on the uterine washings but the SF-SCL group had lower endometrial catalase (0.5 vs. 0.79 U/mg protein, P<0.001) and glutathione peroxidase (GPx; 2.0 vs. 2.43 nmol NADPH/min/mg protein, P=0.04) activity, as well as higher lipid peroxidation (28.5 vs. 17.43 nmol MDA/mg of protein, P < 0.001) and superoxide dismutase (SOD) activity (44.77 vs. 37.76 U; P=0.04). There were no differences in the endometrial reactive species (RS) between the groups. In conclusion, the periovulatory endocrine milieu regulates the endometrial proliferation but without alterations in polyamine metabolism and also modulates the uterine redox environment in beef cattle (AU)

FAPESP's process: 12/23532-5 - Effect of the periovulatory endocrine milieu on polyamines synthesis pathway in endometrium during the first week of the estrous cycle in cattle
Grantee:Roney dos Santos Ramos
Support Opportunities: Scholarships in Brazil - Doctorate (Direct)