检测致突变(致癌)物质的简易法

螺胚以羟基脲处理使其大多数细胞分裂同步后,以各种化学品或药物处理之,然后测定螺胚增长与对照组比较,凡能损伤DNA的物质均使螺胚增长放慢.此法能检测环境中各类物质的致突变性(致癌性).

A SIMPLE MODEL FOR DETECTION OF MUTAGENIC (CARCINOGENIC) SUBSTANCES

A model previously used to screen antitumor drugs was modified for detection of mutagenic (carcinogenic) substances. Cells of snail embryos were synchronized by hydroxyurea for 5.5 hours at G/S borderline. After the release of hydroxyurea inhibition, cells rapidly entered into the S-phase the when was time of chosen to attack the replicating DNA with various gents. The time required to repair the damaged DNA before it could resume its normal function was the time lag of growth of the embryo as compared with the control which was continuously inhibited with hydroxyurea at the same time (2.5h) by the attacking agent.The author had tested six drugs to determine which was potentially to inflict damage to DNA. The result is as follows: mechlo-rethamine (an alkylating agent), mitomycin C (a known mutagen) and 5-fluorouracil (an antimetabolite for cancer therapy) are all capable of damaging DNA, while chloramphenicol (an antibiotics), ascorbic acid (vitamine C) and analgen (a pain-relief drug) are not.Measurement of the length of snail embryo under the microscope is quite easy and relative position of growth-curves plotted on the figures is so meaningful that no statistical analysis is required. An agent which had damaged DNA would cause delayed growth of the embryo and its growth-curve thus lies below that of the control. On the contrary, if an agent Is non-toxic to DNA, the growth of the embryo is, however, faster than the control and its growth-curve lies above that of the control.