ビタミンA過剰投与と他の催奇形因子(コーチゾン,トリバンブルー,騒音,ウレタン,コンドロイチン硫酸)との併用による奇形発生について

抄録

With ddN strain mice, experiments were performed on synergic action between vitamin A and other teratogenic factors and on whether they could together produce malformation in such doses as failed to produce in separate application.
1) Intramuscular injection of 10, 000 I. U. of vitamin A and 2.5mg of cortisone were given together consecutively for 4 days beginning from the 10th day of pregnancy, and cleft palate and toe malformation (tetradactylia or adhesion of toes) coud be produced in 100%.
2) When subcutaneous injection of 0.2cc of 1% trypan blue solution on the 7th day of pregnancy was followed by intramuscular injection of 5, 000 I. U. of vitamin A for 4 days from the 10th to 13th day, malformations were produced in 20.7% of embryos, indicating synergic action between trypan blue and vitamin A.
3) Daily subjection to white noise of 100 phon for 6 hours in combination with daily intramuscular injecticn of 5, 000 I. U. of vitamin A from the 10th to 13th day of pregnancy failed to show any coeffectiveness.
4) Subcutaneous injection of 0.2cc of 10% urethan solution on the 9th day of pregnancy, followed by intramuscular injection of 5, 000 LU. of vitamin A from the 10th to 13th day produced malformation in 30% of embryos, indicating synergic action between them.
5) Intramuscular cortisone 0.7mg, subcutaneous 2% chondroitin sulfate 0.7cc and intramuscular vitamin A 3, 000 I.U, could, in combination, produce malformatin in 19.7%% and cleft palate in 15.8% of embryos, although separately they failed to produce any malformation.
From these results, it is considered that even weak subthreshold teratogenic factors, not speaking of strong superthreshold ones, could easily produce malformation when they are accumulated. It is subsuquently necessary for mothers to be cautious even against weak factors in early pregnancy.