1997 Volume 43 Issue 6 Pages 480-486
The purpose of this study was to examine differences in the effects of the intraamniotic administration of physiological saline between a hysterotomy group (exo utero) and an extrauterine injection (in utero) group. We also checked for variant rugae in mouse embryos in which cleft palate did not develop.
On day 12 or 13 of gestation, 2μl of physiological saline was injected into the amniotic cavities of pregnant mice, either by hysterotomy or by extrauterine injection. The embryos were removed from these mice 18 days later.
The embryo survival rate was low in the hysterotomy group. It was therefore not possible to examine the incidence of cleft palate and variant rugae in this group. The incidence of cleft palate and variant rugae in the extrauterine injection group differed significantly from that in the untreated control group. The results indicate that extra-uterine injection is recommended for intra-aminiotic administration of test compounds in toxicological studies. The features of variant rugae differed largely depending on the gestational age at which surgery was performed. This may be useful as an indicator of teratogenicity.
