Silva Liege Cristina Garcia, Regazzi Fernanda Machado, Lúcio Cristina Fátima, Veiga Gisele Almeida Lima, Angrimani Daniel Souza Ramos, Fernandes Claudia Barbosa, Vannucchi Camila Infantosi
Department of Animal Reproduction, School of Veterinary Medicine and Animal Science.
Anim Reprod. 2018 Aug 16;15(1):51-55. doi: 10.21451/1984-3143-2017-AR0054.
During pregnancy, fetal lambs are exposed to low oxygen tension. Thus, an effective antioxidant mechanism is partially developed which sensitizes fetus to oxidative stress. Consequently, term and preterm neonates are susceptible to molecular and cellular injury caused by oxygen species (ROS). This study aimed to evaluate the development of antioxidant enzymes and oxidative profile of preterm (135 days of pregnancy) and term (145 days of pregnancy) neonatal lambs, correlating with clinical analysis. Preterm lambs had significantly (P ≤ 0.05) lower score of vitality (4.00 ± 1.10), bradycardia (99 ± 34 bpm) and bradypnea (13 ± 10 mpm). However, both groups were normothermic and euglycemic. Preterm group had low blood pH (7.07 ± 0.10) and both groups had hypercapnia, more severe in preterm group (85.52 ± 18.65 mmHg). In addition, premature newborns had lower pO (10.67 ± 5.65 mmHg) and SO (6.17 ± 5.85%) values. No significant difference (P ≥ 0.05) on antioxidant enzymes and oxidative stress were verified among experimental groups, although glutathione peroxidase negatively correlated with Apgar score, heart rate, SO and pO. Our data show that preterm neonates are less adapted to the odds of labor and to overcome the immediate changes of extra-uterine life. Furthermore, we verified an influence of glutathione peroxidase in controlling oxidative stress, which highlights mature enzymatic mechanisms of cell redox, even in premature lambs.
在孕期，胎羊会暴露于低氧张力环境。因此，一种有效的抗氧化机制会部分发育，这使胎儿对氧化应激敏感。结果，足月和早产新生儿易受氧自由基（ROS）引起的分子和细胞损伤。本研究旨在评估早产（妊娠135天）和足月（妊娠145天）新生羔羊抗氧化酶的发育及氧化状态，并与临床分析相关联。早产羔羊的活力评分（4.00±1.10）、心动过缓（99±34次/分钟）和呼吸过缓（13±10次/分钟）显著更低（P≤0.05）。然而，两组均体温正常且血糖正常。早产组血液pH值较低（7.07±0.10），两组均有高碳酸血症，早产组更严重（85.52±18.65 mmHg）。此外，早产新生儿的pO（10.67±5.65 mmHg）和SO（6.17±5.85%）值更低。尽管谷胱甘肽过氧化物酶与阿氏评分、心率、SO和pO呈负相关，但各实验组在抗氧化酶和氧化应激方面未发现显著差异（P≥0.05）。我们的数据表明，早产新生儿对分娩的不利因素及克服宫外生活的即刻变化适应能力较差。此外，我们证实了谷胱甘肽过氧化物酶在控制氧化应激中的作用，这凸显了细胞氧化还原的成熟酶机制，即使在早产羔羊中也是如此。
