1990 年 55 巻 4 号 p. 581-588
The bactericidal broad spectrum drug Norbactin containing Norfloxacin has been proved to be genotoxic when human dose equivalent of it was orally administered into mice. The frequency of bone marrow chromosome aberrations assessed in 6 intervals between 15 min and 7th week and the micronucleated erythrocytes and first spermatocyte metaphase chromosome aberrations assessed in 6 hr, 30 hr and 72 hr and sperm with abnormal head morphology assessed in 6 hr, 30 hr, 72 hr, 1st wk and 7th wk was significantly high than that of normal specimens. All the four testing parameters were found to have dose-effect relationship when different set of mice were orally administered with 1/2, 1 and 2 doses of Norbactin. Therefore, like antibiotics of biological origin, the broad spectrum antibactericidal Norbactin belonging to the new class “Fluoro quinolones” has been found to be genotoxic agent by a battery of tests in experimentally treated mice.