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| Author(s): |
Leticia Lima de Almeida
Total Authors: 1
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| Document type: | Master's Dissertation |
| Press: | São Paulo. |
| Institution: | Universidade de São Paulo (USP). Faculdade de Medicina Veterinária e Zootecnia (FMVZ/SBD) |
| Defense date: | 2018-04-27 |
| Examining board members: |
Camila Infantosi Vannucchi;
Maria Lucia Gomes Lourenço;
Gisele Almeida Lima da Veiga
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| Advisor: | Camila Infantosi Vannucchi |
| Abstract | |
Newborns have an immature antioxidant system, due to low oxygen exposure in intrauterine environment during fetal life. Immediately after birth, sudden changes of physiological and environmental conditions cause a significant increase in oxygen consumption, resulting in the production of free radicals. These conditions turn the newborn vulnerable to the negative effects of oxidative stress, which potentially can impair neonatal vitality. This study aimed to compare the antioxidant profile and oxidative stress of neonates and canine females during vaginal labour or elective cesarean section, and to evaluate whether the obstetric condition influences their oxidative status. For this purpose, 21 pregnant bitches were subjected to two experimental groups, according to the obstetric condition: Vaginal Eutocia (n = 10) and Elective Cesarian Section (n = 11) and their respective newborns were allocated into subgroups according to the obstetric condition and moment of birth: Inicial Vaginal Eutocia (n=10), Final Vaginal Eutocia (n = 9), Inicial Elective Cesarian Section (n = 11) and Final Elective Cesarian Section (n= 10). Bitches were evaluated during the preparatory phase of whelping, intrapartum; one and 72 hours postpartum, when blood samples were collected for analysis of the antioxidant profile [Superoxide Dismutase (SOD) and Glutathione Peroxidase (GPx) activity enzymes assays, Total Antioxidant Capacity (TAC) assay and Total Thiols Concentration assay] and oxidative stress [lipid peroxidation (TBARS) and protein oxidation assays]. Neonates were evaluated for the Apgar score at 0 and 60 minutes of birth; clinical evaluation (heart and respiratory rates; muscle tone, irritability reflex and mucous color score; and body temperature), blood lactate, pulse oximetry, determination of antioxidant profile and oxidative stress, and body weight measurement at 0, 60 minutes, 12, 24 and 72 hours after birth. The Vaginal Eutocia bitches had higher lipid peroxidation, protein oxidation and SOD activity and lower GPx activity and total thiols concentration in comparison to the Elective Cesarian Section Group. Total antioxidant capacity was higher 1 hour postpartum compared to the others evaluation moments in the Elective Cesarian Section Group. Although neonates from the Vaginal Eutocia Group presented better neonatal vitality than those from the Elective Cesarian Section, all neonates presented adequate evolution of the Apgar score, mucous color, irritability reflex, muscle tone and pulse oximetry 1 hour postpartum. Blood lactatemia was higher in the Vaginal Eutocia Group, as well as for the last neonates. Lipid peroxidation was higher in neonates born by vaginal eutocia compared to those born by elective cesarean section, whereas protein oxidation was higher in the first neonates born by vaginal eutocia compared to those born at the end of delivery. Conversely, Elective Cesarian Section neonates born at the end of surgery had higher protein oxidation. In addition, for those neonates born at the end of delivery, the Elective Cesarian Section group presented higher protein oxidation compared to the Vaginal Eutocia group. Furthermore, GPx activity was higher in neonates born by elective caesarean section. In conclusion, the obstetric condition imposes differences in the oxidative and antioxidant profile in bitches and neonates with similar oxidative status, denoting maternal influence on the oxidative balance of the newborns. (AU) | |
| FAPESP's process: | 16/24731-2 - Oxidative stress and antioxidant profile evaluation in the neonatal period of puppies born by vaginal eutocia or elective cesarean section |
| Grantee: | Leticia Lima de Almeida |
| Support Opportunities: | Scholarships in Brazil - Master |