METABOLIC-ACTIVATION OF 4 DRUGS IN THE EYE MOSAIC ASSAY MEASURING PRINCIPALLY MITOTIC RECOMBINATION IN DROSOPHILA-MELANOGASTER - DIFFERENCES IN STRAIN SUSCEPTIBILITY AND ROUTE OF EXPOSURE

One mycotoxin and three therapeutic drugs widely used in developing co untries were examined for genotoxic activity by means of w/w + somatic recombination assay. Streptozotocin (SZ), an antibiotic antineoplasti c agent, gave a frequency of light spots almost one order of magnitude higher than those obtained with the carcinogen mycotoxin sterigmatocy stin (STC), the antiprotozoal and antimicrobial metronidazole (MNZ), a nd the antifungal griseofulvin (GF). Thus the order of response was SZ >STC>MNZ>GF. Chronic treatment turned out to be the better route of ex posure for these genotoxins when compared with surface treatment. The performance of the insecticide-resistant strain Hikone-R was better th an that of the wild genotype LS (Leiden Standard). The positive test r esults obtained with all four chemicals showed that the P450 system of Drosophila is capable of metabolizing these genotoxins into electroph ilic intermediates.