Development of the Test Method for Teratogenesis of Certain Chemicals Using Fertilized Fish Egg.

某些化学物质，包括几种药物的tartatogenesis进行了测试受精鱼卵。如果这项研究取得成功，将可缩短进行致畸试验所需的时间，并使我们能够避免在试验的第一个筛选阶段使用恒温动物。将化学物质引入胚胎是通过将化学物质直接显微注射到受精卵中或将它们浸入化学物质溶液中来进行的。正如我们所观察到的，微量注射方法的缺点有两个方面：第一，蛋黄从注射部位移位到蛋的外部，第二，当绒毛膜厚时，注射过程中的并发症是不可避免的;这两个缺点都导致实验结果的精确度损失。浸渍法有其自身的问题，即化学品通过绒毛膜的渗透性取决于它们的分子量和/或化学品性质。因此，我们避免了微量注射法，而采用浸渍法来研究（1）绒毛的软化和消化;（2）相对低分子量的化学物质的致畸作用。在第一个实验中，我们成功地建立了一种从鳉鱼（Hi-Medaka）中提取绒毛膜酶的新方法。在第二个实验中，我们发现每种致畸化学物质都在胚胎的个体发育阶段诱发。鸡蛋中的残留化学物质的量也通过一种新的分析方法测定，具有更好的精度。

Taratogenesis of certain chemicals including several medicines was tested on fertilized fish eggs. A successful outcome of such a study will shorten the time required for the test of teratogenesis and enable us to avoid the use of homeothermic animals in the first screening stage of the test. Introduction of chemicals into the embryo was performed either by direct micro-injection of chemicals into fertilized eggs or by dipping them in solutions of chemicals. shortcomings of the micro-injection method, as we observed, were twofold : first, there was a displacement of yolk from the site of injection to the outside of the egg and, secondly, a complication in the injection procedure was inevitable when the choriion was thick; both leading to a loss of precision in the experi-mental outcome. The dipping method has its own problem that the permiability of chemicals through chorion depended on their molecular weights and/or chemicals properties. We therefore avoided micro-injection method and used the dipping method to study (1) softening and digestion of chorion and (2) the teratogenesis of chemicals of relatively of low molecular weight. In the first experiment we were successful in establishing a new procedure for the extraction of chorio-nase from killifish (Hi-Medaka), and in the second we discovered that each teratogenic chemicals induced on the ontogenical stage of the embryo. The amount of residual chemicals in the egg was also determined by a new analytical method with better precision.