official journal of Congeital Anomalies Research Association of Japan
Online ISSN : 2433-1503
Print ISSN : 0037-2285
EFFECTS OF VITAMIN B_<12> ON THE INCIDENCE OF MALFORMATIONS IN THE RAT FETUS CAUSED BY MATERNAL HYPERVITAMINOSIS-A
Toshio Yamaguchi
Author information
JOURNAL FREE ACCESS

1968 Volume 8 Issue 1 Pages 19-30

Details
Abstract

This study was done in order to examine the effects of vitamin B_<12> on the manifestation of malformations in the Wistar rat fetus due to maternal hypervitaminosis-A during pregnancy . The hypervitaminosis-A in the pregnant rats was produced by oral administrations of vitamin A at a dose of 30,000 I.U./100g body weight from the 10th to the 13th day of pregnancy. The vitamin B_<12> was administered subcutaneously at a dose of 1.0γ/100g (small dose) or 10γ/100g (large dose) at the same gestational days of vitamin A administrations. The results were as follows: 1. The simultaneous administrations of vitamin B_<12> either at the small or large dose, revealed an action to reduce the adverse effect of hypervitaminosis-A on the fetal growth. 2. The incidence of gross malformations in the offsprings was 38.6 % in the group treated with both vitamin-A and the small dose of vitamin B_<12> while thc incidence was 82.6%; in that treated with vitamin A alone. Among the malformations manifested in this experiment, facial malformations such as microtia, open eyelid, macroglossia, macrognathia, cleft palate and lower jaw cleft were predominant. In the group treated with vitamin A and the large dose of vitamin B_<12> on the contrary, the incidence of gross malformations was not so different from that in the group treated with vitamin A alone. 3. The growth of thc fetal skeletons was examined in the states of ossification of the occipital bone, sternebrae, metacarpi, metatarsi and coccyges. Neither the small nor large dose of vitamin B_<12> affected markedly the retardation of ossification due to hypervitaminosis-A. 4. The small dose of vitamin B_<12> brought about an apparent preventive effect on thc manifestations of the 14th rib, brachygnathia and the malformations of the long bones of extremities due to hypervitaminosis-A. On the contrary, the administration of the large dose showed a tendency to increase the number of the fetuses with brachygnathia, malformed humerus or the 14th rib due to hypervitaminosis-A.

Content from these authors
© 1968 The Japanese Teratology Society
Previous article Next article
feedback
Top