2011 (SBTE) 25th Annual Meeting Proceedings - International ...

Acta Scientiae Veterinariae, 2011. 39(Suppl 1): Abstracts - 25th Annual Meeting SBTE-Brazil. August 2011.
A189 EMBRYOLOGY, BIOLOGY OF DEVELOPMENT AND PHYSIOLOGY OF REPRODUCTION
INDUCTION OF PAR
ARTURITION
WITH AGLEPRIST
GLEPRISTONE IN EWES
Fernanda Machado Regazzi, Liege Garcia Silva, Gisele Almeida Lima Veiga, Cristina Fátima Lucio, Guilherme Cain de Oliveira,
Daniel Souza Ramos Angrimani, Claudia Barbosa Fernandes & Camila Infantosi Vannucchi
DEPARTAMENTO DE REPRODUÇÃO ANIMAL - FMVZ - USP, SÃO PAULO, SP, BRAZIL.
The maintenance of pregnancy in mammals requires the binding of progesterone to its endometrial receptor, promoting the
proliferation of epithelial and vascular uterine cells. In sheep, increases in production of progesterone are essentially of placentary origin after 50
days of pregnancy. Placental progesterone is sufficient to maintain pregnancy in the absence of the corpus luteum. Antiprogestagens of indirect
action, such as corticosteroids and analogs of the prostaglandin F2α, lead to luteolysis but interval between treatment and labor is variable and
lengthy. The use of aglepristone for this purpose shows satisfactory results in some species such as cows and goats. The aglepristone is an active
antiprogestagen that acts in late pregnancy, as a competitive inhibitor of the uterine progesterone receptor causing the end of pregnancy. So far,
there are no reports of the aglepristone as an inducer of labor in sheep. The assessment of an efficient protocol for induction of parturition in sheep
can provide appropriate medical intervention in cases of pregnancy toxemia, prolonged pregnancy or for the synchronization of delivery. The aim
of this study was to assess the efficacy of aglepristone (Alizin ® ) to induce parturition in pregnant ewes, especially during the period of pregnancy
in which placental progesterone synthesis is still intense, and observe possible side effects. Pregnant ewes were allocated into 2 groups: preterm
group I that received aglepristone with 133 days of gestation (n = 4, 3 twin pregnancies) and preterm group II that received treatment with 143
days of gestation (n = 4, 2 twin pregnancies). Ewes received two subcutaneous (SC) injections (0.33 mL / kg / day) of aglepristone 24 h apart.
Means were compared by student’s “t” test (P = 0,05). For ewes of the group I, the first signs of labor were noted 44h±5h after the first injection
of aglepristone. The group II showed interval between the first medical induction and labor of 40h±3h, with no statistical difference between
groups (P= 0,25). No statistical difference (P = 0,07) was observed between labor induction and parturition in singleton pregnancies (38h ± 2
h) compared to twins (44h ± 4h). It was observed that aglepristone effectively induced labor in all ewes, regardless of treatment. The complete
elimination of fetal membranes was observed after 8h±2h of fetal expulsion in group I and after 4h±2h in group II. Only one animal from group
I had retained placenta, with time of placenta expulsion of more than 12 h (12 h and 55 min). This study demonstrated, for the first time, that
aglepristone can be used for the induction of parturition in sheep with satisfactory efficiency, both in single and twin deliveries, with no significant
side-effects. [Support and acknowledgments Virbac Animal Health].
Keywords: parturition, aglepristone, ewes.
A190 EMBRYOLOGY, BIOLOGY OF DEVELOPMENT AND PHYSIOLOGY OF REPRODUCTION
EVIDENCE OF THE NITRIC OXIDE IMPORTANCE TO IN VITRO DEVELOPMENT OF BOVINE EMBRYO
Priscila Di Paula Bessa Santana 1 , Thiago Velasco Guimarães Silva 1 , Bruno Baraúna da Silva 1 , Nathália Nogueira da Costa 1 , Davi
César Nascimento dos Santos 1 , Stefanne Dhullia Braga Conceicão 1 , Marcela da Silva Cordeiro 2 , Simone do Socorro Damasceno
Santos 1 , Otávio Mitio Ohashi 1 & Moysés dos Santos Miranda 1
1
UFPA, BELEM, PA, BRAZIL. 2 IFPA, BELEM, PA, BRAZIL.
N
Nitric Oxide (NO) has multiple cellular functions by acting as a cellular messenger or reacting with oxigen reactive species for cell
protection (2005, Molecular Aspects of Medicine 26, 3-31). The role of NO during bovine pre-implantational development is unknown. The
goal of this work is to evaluate the importance of NO production during the in vitro culture of bovine embryos in an indirect way by using a NO
sinthesis inhibitor (L-NAME; N-nitro-L-Arginine Metil Ester). Bovine COCs obtained from ovaries of the slaughterhouse were in vitro
matured in TCM199 supplemented with 0.5 µg/mL of FHS, 50 µg/mL of LH, 50 µg/mL of gentamicin, 10 mg/mL of pyruvate and 10% of FBS
for 24h. Groups of 20 mature oocytes were fertilized with 2X106 of spermatozoa/drop for 24h. The presumptive zygotes were cultivated for 8
days in SOF medium (suplemmented with 50 µg/mL of gentamicin, 0,6 mg/mL of BSA, 5% de FBS) in an incubator at 38.5°C and 5% CO2
in air. For the experiment 10 mM of L-NAME and 200 mM of Glutamine (Gln), an aminoacid which leads to NO production (1999, Journal of
Surgical Research 86, 213-219) were added to SOF medium according to the experimental groups: SOF medium alone (SOF), SOF medium
with L-NAME (SOF-NAME), SOF medium with Gln (SOF-Gln), and SOF medium with Gln and L-NAME (SOF-Gln-NAME). Cleavage
and blastocyst rates of the groups SOF (n = 120), SOF-NAME (n = 131), SOF-Gln (n = 119), e SOF-Gln-NAME (n = 127) were evaluated
at 2nd and 8th day of culture, respectively. The results of 6 repetitions were analyzed by ANOVA and Bonferroni post-hoc test and significance
level of 5%. Cleavage rates were similar between the treatments (P > 0.05). Treatment with L-NAME impaired bovine embryo production only
in the absence of Gln (rates of 22,16% and error of median of 5,27 vs. 33,75% ± 6,06 vs. 38,80% ± 4,13 for SOF-NAME, SOF and SOF-Gln-
NAME; P< 0,05). Also, supplementation of SOF medium with Gln only had no effect on the embryo production rate (rates of 49,11% and error
of median of 6,44 vs. 33,75% ± 6,06 to SOF-Gln and SOF respectively; P > 0,05). The results suggest that the NO production it seems to be
important to in vitro development of bovine embryos, and the addition of Gln can reverse the effect of L-NAME on the embryo culture .
Complementary studies has been doing to evaluate directly the production and the importance of NO at specific moments during bovine embryo
development in ivtro. [Acknowledgements: CNPq, FAPESPA and UNOPAR].
Keywords: bovine, ivc, nitric oxide.
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