Table 1

Fetal structural anomalies in pregnant CD-1 mice administered 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), with or without pretreatment using the cytochromes P450 inducer phenobarbital1-a

Saline vehicle160None
NNK (GDs 10 and 11)142Open eyelid1
NNK (GDs 11 and 12)145Open eyelid1
NNK (GDs 12 and 13)87Open eyelid1
Cleft palate1
Phenobarbital + NNK (GDs 11, 12)163Exencephaly1-c 2
Kinky tail1-c 1
Cleft palate2
  • n, Number of fetuses.

  • 1-a NNK (100 mg/kg ip) was administered on two consecutive gestational days (GDs) at three different times during organogenesis. Pretreatment with phenobarbital (60 mg/kg ip) was administered on GDs 8, 9 and 10.

  • 1-b There were no skeletal anomalies, ectopic kidneys or hydrocephaly in any groups.

  • 1-c Anomalies seen in fully formed fetuses that were born dead.