HYPERTHERMIA AS A TERATOGEN - PARAMETERS DETERMINING HYPERTHERMIA-INDUCED HEAD DEFECTS IN THE RAT
HYPERTHERMIA AS A TERATOGEN - PARAMETERS DETERMINING HYPERTHERMIA-INDUCED HEAD DEFECTS IN THE RAT
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DOI：
10.1002/tera.1420310212
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发表时间：
1985-01-01
期刊：
影响因子：
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通讯作者：
EDWARDS, MJ
中科院分区：
文献类型：
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作者：
GERMAIN, MA;WEBSTER, WS;EDWARDS, MJ
研究了大鼠胚胎发育关键期温度升高的持续时间和程度与先天性畸形诱导的关系。妊娠9天12小时（原肠胚期）的Sprague-Dawley大鼠部分浸泡在水浴中，直至其核心温度通过直肠热敏电阻探头监测升高到指定温度。从40.5度开始测试了7个温度。C-43.5.degree。C，海拔2.0-5.0度。核心温度为C。在这些温度下的不同持续时间测试了潜在的致畸性。一次海拔5.0度。摄氏或4.5度。C只需要一个持续时间的峰值就会致畸，4.0度。C在5分钟内致畸，3.5度。10分钟内C， 3.0度。摄氏20分钟，2.5度。1小时内升高摄氏2.0度。C作用8 h无致畸性。在所有致畸温度下，小眼是最常见的畸形，并且经常是在特定温度下最短暴露时间内看到的唯一畸形。脑膨出、面部裂、上颌发育不全是常见的畸形。5只对照大鼠置于38℃水浴2 h。C使其海拔升高2.5度。C作用1 h为致畸的阈值组合。当温度上升到2.5度以上时。C升高导致致畸的必要暴露时间减少。
The relationship between the duration and extent of temperature elevation, during a critical period of rat embryonic development and the induction of congenital malformations was determined. Pregnant Sprague-Dawley rats, at 9 days 12 h gestation (gastrulation stage), were partially immersed in a water bath until their core temperature, monitored by a rectal thermistor probe, was elevated to a nominated temperature. Seven temperatures were tested from 40.5.degree. C-43.5.degree. C, elevations of 2.0-5.0.degree. C in core temperature. Various durations at each of these temperatures were tested for potential teratogenicity. A single elevation of 5.0.degree. C or 4.5.degree. C needed only a spike in duration to be teratogenic, 4.0.degree. C was teratogenic within 5 min, 3.5.degree. C within 10 min, 3.0.degree. C within 20 min and 2.5.degree. C within 1 h. An elevation of 2.0.degree. C for 8 h was not teratogenic. Microphthalmia was the most common malformation at all teratogenic temperatures and was frequently the only malformation seen at the shortest time exposure for a particular temperature. Encephalocele, facial clefting and maxillary hypoplasia were the other frequently seen malformations. Five control rats were placed in the water bath for 2 h at 38.degree. C so that their elevation of 2.5.degree. C for 1 h was the threshold combination for teratogenesis. As the temperature increased above a 2.5.degree. C elevation the necessary duration of exposure for teratogenesis decreased.