BENZIDINE-INDUCED AND DIAMINOBENZIDINE-INDUCED MICRONUCLEI IN MICE AFTER INTRAPERITONEAL AND ORAL SINGLE OR MULTIPLE TREATMENT

The capacity of benzidine and its derivative diaminobenzidine to induc e micronuclei in bone marrow polychromatic erythrocytes was tested in two mouse strains, C57BL/6 and BALB/c, after intraperitoneal injection or gavage on one, two or three successive days. Results observed afte r multiple intraperitoneal dosages were inconclusive for both compound s, when tested in C57BL/6 mit e. On the other hand, benzidine induced a marked increase in the micronucleated polychromatic erythrocyte freq uency after a single intraperitoneal treatment in BALB/c mice. Oral tr eatment with both chemicals had a genotoxic effect in both mouse strai ns, although in BALB/c mite a significant increment in micronucleated cell frequency was observed only after two or three consecutive doses. We conclude that diaminobenzidine has a genotoxic activity comparable to benzidine, presenting specific strain and administration route eff ects.