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

在受精鱼卵上测试了包括几种药物在内的某些化学物质的成垢作用。这项研究的成功结果将缩短致畸测试所需的时间，并使我们能够避免在测试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微量注射到受精卵中或将其浸泡在化学物质的溶液中进行的。正如我们所观察到的，微量注射方法有两个缺点：第一，卵黄从注射部位移位到卵子外面；第二，当绒毛膜很厚时，注射过程中的并发症是不可避免的；两者都导致实验结果的精确度降低。浸渍方法有其自身的问题，即化学物质通过绒毛膜的渗透性取决于它们的分子质量和/或化学性质。因此，我们避免了微量注射的方法，而使用浸渍方法来研究(1)绒毛膜的软化和消化，(2)相对低分子质量的化学物质的致畸作用。在第一个实验中，我们成功地建立了从剑鱼(Hi-Medaka)中提取绒毛膜酶的新程序，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导。用一种新的分析方法测定了鸡蛋中的化学物质残留量，具有较高的精密度。

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.