EXPERIMENTAL STUDIES ON THE CO-OPERATIVE TERATOGENIC EFFECT BY NOISE-STIMULATION AND TRYPAN BLUE

This experiment was performed in the mice of ddN strain to observe the co-operative teratogenic effect by two agents, each of which showed hardly teratogenic activity for oneself.In the controlled group A, 0.2cc of 1% trypan blue solution was injected to the female mice on the 8th day of pregnancy.In the controlled group B, the noise of 100 phon was given them for 6 hours daily from thellth day to 14th day of pregnansy.In the experimental group, both of the treatments described above were administered the pregnant female mice.All the embryos were examined on the 18th day of pregnancy.The results obtained were as follows:(1) In the group A only one case of cleft palate was observed in 59 embryos, and in the group B only one case of polydactylia was observed in 129 embryos. But, in the experimental group, 14 cases of malformation were observed in 82 embryos; they were one case of encephalocele, six tail defect, six polydactylia and one toe defect.(2) The embryos in the experimental group were dead or absorbed more frequently than in any other group.(3) As regards the average weight and prematurity of embryos, significant difference was not seen among the three groups.(4) From those results, it may be possible that malformed or dead infants are more frequently born if the women in the early stage of pregnancy are subjected to more than two teratogenic factors, even though each of these factors may be as weak as threshold.