青蛙蝌蚪微核试验——一种水体诱变剂检测系统的建立

ESTABLISHMENT OF A TESTING SYSTEM, THE MICRONUCLEUS TEST ON FROG TADPOLE, TO DETECT MUTAGENS IN WATER BODY

以青蛙蝌蚪为实验生物,利用甲基磺酸乙酯(EMS)和亚硝基胍(MNNG)探讨其化合物浓度、暴露时间和蝌蚪发育阶段等因素对诱发青蛙蝌蚪红细胞微核的影响,不同统计单位的特点和相互关系;提出了青蛙蝌蚪微核试验作为一种水体诱变剂检测系统的基本实验程序和一般原则。此外,还描述了“小体M”——一种特殊的细胞学现象,并初步讨论了微核代谢机制。

An investigation was made on the effects of chemical concentration, exposure time and developmental stage of the tadpole on the induction of mieronuclei in the erythrocytes of the forg tadpole (Rana nigromaculata) by two chemicals, ethyl methanesulphonate and Nmethyl-N'-nitro-N-nitrosoguanidine. Characters and correlations among several testing indices were analysed. Suggestions were made on the basic procedures and principles for a testing system, the micronucleus test on frog tadpole, for the detection of mutagens in aquatic environments. Besides, a unique cytological structure, the 'Small body', was described, and the metabolic mechanism of micronuclei was discussed preliminarily. The testing system is sensitive, standardized and practical. It can be used not only for screening mutagens in water body and evaluating genotoxicity of chemicals, but also for detecting mutagenic activity of polluted fresh-waters.