Barr M, Beaudoin A R
Teratology. 1981 Oct;24(2):163-7. doi: 10.1002/tera.1420240207.
Pregnant Wistar rats were injected with hydroxyurea (HU) intraperitoneally (IP) t one of several 6-hour intervals on days 9-10.75 to study the role of circadian growth variations in the teratologic response of the fetuses. Two stocks of rats were studied and the results in each compared. The fetal response to HU, as observed at day 21, was not detectably modified by circadian fetal growth variation. No correlations between hour of HU administration and fetal weight, placental weight, resorption, or total malformation rates were found. Cyclic variations in the incidence of hydronephrosis and left umbilical artery was observed, but it was not clear that these were related to maternal light:dark cycles. Difference of response between two stocks of rats included marked variation in the incidence and type of malformations and variations in the timing of peak incidence for some but not all malformations.
在妊娠第9至10.75天，对怀孕的Wistar大鼠在几个6小时间隔中的某一个时间点进行腹腔内注射羟基脲（HU），以研究昼夜生长变化在胎儿致畸反应中的作用。研究了两批大鼠，并对每批的结果进行了比较。在第21天观察到，胎儿对HU的反应并未因胎儿昼夜生长变化而发生可检测到的改变。未发现HU给药时间与胎儿体重、胎盘重量、吸收或总畸形率之间存在相关性。观察到肾盂积水和左脐动脉发生率的周期性变化，但尚不清楚这些变化是否与母体的光暗周期有关。两批大鼠之间的反应差异包括畸形发生率和类型的显著变化，以及部分（而非全部）畸形发生率峰值出现时间的变化。
