S-Space College of Medicine/School of Medicine (의과대학/대학원) Dept. of Medicine (의학과) The Seoul Journal of Medicine The Seoul Journal of Medicine Vol. 28 No.2 (1987)
Experimental Neural Tube Defect Induced with Hypervitaminosis A in the Rat
Vitamin A 과량투여가 태자의 신경관 결손에 미치는 영향에 관한 실험적 연구
- Issue Date
- Seoul J Med, Vol.28 No.2, pp. 91-108
- Neural tube defect ; Exencephaly ; Anencephaly ; Spina bifida ; Fetal mortality ; Critical period ; Gestational period
- The causes of human neural defect (NTD) are not clarified yet and there is a
multitude of theories on the morphogenesis of this malformation.
This experiment was carried out to develop a model for NTD in animal and elucidate the
morphogenesis of NTD with particular emphasis on the relationship between exencephaly and
With exposure to 150,000 IU of vitamin A on various periods of gestation, ranging from the
7th to the 10th days, not only NTDs but a variety of other systemic malformations such as
anophthalmia, exophthalmia, anotia, maxillary and/or mandibular hypoplasia, tail and/or genital
agenesis, anal atresia and limb defects were produced.
Occurrence of these malformations was more related to the time of exposure than the dose
of vitamin A, i. e. NTD could be induced only with exposure on the 8th and 9th days of
gestation. It was also possible to mention that the critical period of ex-/anencephaly is the
8th day of gestation and that of spina bifida the 9th day in rats.
In addition to the teratogenicity 150,000 IU of vitamin A caused marked increase in fetal
mortality and growth retardation if administered before the IOth day of gestation.
Observations of the degenerative changes and necrosis in the exencephalic brains in variable
extent made it possible to conclude that the classical anencephalic features result from
the spontaneous necrosis of the exencephalic malformation.