Relationship of fetal growth to duration of heat stress in an ovine model of placental insufficiency
Relationship of fetal growth to duration of heat stress in an ovine model of placental insufficiency
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DOI：
10.1016/s0002-9378(99)70629-0
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发表时间：
1999-05-01
影响因子：
9.8
通讯作者：
Battaglia, FC
中科院分区：
文献类型：
--
作者：
Galan, HL;Hussey, MJ;Battaglia, FC
目的：在绵羊模型中，从妊娠35天开始暴露于环境热应激80天后发生宫内生长受限。我们的目的是确定宫内生长受限在暴露55天后消除热应激是否可逆;也就是说，在发育的关键点短暂暴露是否足够？研究设计：5只妊娠母羊在妊娠35天开始暴露于热应激，暴露55天后取出。在对照组中的5只母羊作为同期对照进行了研究，并添加到先前研究的对照组中的37只母羊的数据中。从妊娠50天开始，获得一系列胎儿生物超声测量值（双顶径、腹围、股骨长度和胫骨长度）。计算每个参数的生长曲线，并将暴露于热应激55天的组中的胎仔与对照组中的42只胎仔和暴露于热应激80天的先前研究中的4只胎仔进行比较。回归线，95%的置信区间，和斜率被确定为每个studygroup.RESULTS：无论是55天和80天的热暴露组显示出显着减少胎儿和胎盘重量与对照组相比。80天组动物的胎仔和胎盘重量显著低于55天组动物（P
OBJECTIVE: Intrauterine growth restriction in an ovine model occurs after exposure to environmental heat stress for 80 days beginning at 35 days' gestation. Our objective was to determine whether intrauterine growth restriction is reversible on removal of the heat stress after only 55 days of exposure; that is, does a brief exposure at a critical point of development suffice?.STUDY DESIGN: Five pregnant ewes were exposed to heat stress beginning at 35 days' gestation and were removed after 55 days of exposure. Five ewes in a control group were studied as contemporaneous controls and added to data from 37 ewes in a control group previously studied. Serial fetal biometric ultrasonographic measurements (biparietal diameter, abdominal circumference, femur length, and tibia length) were obtained beginning at 50 days' gestation. Growth curves were calculated for each parameter, and comparisons were made between fetuses in the group exposed to heat stress for 55 days and 42 fetuses in the control group and 4 fetuses from a previous study that were exposed to heat for 80 days. Regression lines, 95% confidence intervals, and slopes were determined for each study group.RESULTS: Both the 55-day and the 80-day heat exposure groups showed a significant reduction in fetal and placental weights compared with the control group. Animals in the 80-day group had significantly lower fetal and placental weights than the animals in the 55-day group (P