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
| Treatment | n | Anomalies1-b | n |
|---|---|---|---|
| Saline vehicle | 160 | None | |
| NNK (GDs 10 and 11) | 142 | Open eyelid | 1 |
| NNK (GDs 11 and 12) | 145 | Open eyelid | 1 |
| NNK (GDs 12 and 13) | 87 | Open eyelid | 1 |
| Cleft palate | 1 | ||
| Phenobarbital | 99 | None | |
| Phenobarbital + NNK (GDs 11, 12) | 163 | Exencephaly1-c | 2 |
| Kinky tail1-c | 1 | ||
| Cleft palate | 2 |
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.