抄録
The teratogenicity of ethylenethiourea (ETU) was investigated in rats utilizing the intra-amniotic injection techniques. Nulliparous Wistar-Imamichi female rats were mated overnight with males from the same stock and the day sperm-positive vaginal smears were found was designated as day 0 of pregnancy. Amniotic sacs in one uterine horn were injected with 200 μg of ETU or 2-^<14>C-ETU per 10 μl on day 12 of pregnancy. The embryos in the opposite uterine horn received the same volume of sterile distilled water as a corresponding control. Hydroxyurea (HU) (500-2000 μg/10μl) was also used in order to compare the teratogenicity of the two chemicals. On day 20 of pregnancy, fetuses were recovered and examined for gross external and visceral abnormalities. When 200 μg of 2-^<14>C-ETU was injected into the amniotic sacs, 5-fold increase was evidenced in the incorporation of radioactivity into the embryos as compared with that into the embryos whose mothers were treated orally with a sufficient dose of ETU for producing malformations on the same gestational stage. However, intra-amniotic injection of ETU did not reduce fetal survival and weight and did not cause malformations. On the other hand, HU exerted embryotoxicity and produced various types of malformations in the survived fetuses.
