DETERMINATION OF GENOTOXICITY OF THE METABOLITES OF THE PESTICIDES GUTHION, SENCOR, LOROX, REGLONE, DACONIL AND ADMIRE BY P-32 POSTLABELING

Commercial formulations of the pesticides: Guthion (azinphos methyl), Sencor (metribuzin), Lorox (linuron), Reglone (diquat), Daconil (chlor othalonil) and Admire (imidacloprid) were studied for their genotoxici ty by P-32-postlabeling. Metabolites of the pesticides were obtained e nzymatically using arochlor induced rat liver S9 fraction, in an NADPH generating system, The resulting metabolites were reacted with calf t hymus DNA and the DNA was analyzed for presence of adducts by either t he nuclease P1 or butanol enrichment. Nuclease P1 enrichment resulted in adducts for all the pesticides. Compared to the level of adducts in control DNA, the levels in pesticide-treated DNA were higher for all the pesticides, except Daconil. The increase in adduct numbers for pes ticide-treated DNAs ranged from 4.9-12.4 times the control-DNA indicat ing pesticide genotoxicity in this in vitro system. Enrichment using b utanol extraction gave three adducts unique to Sencor-DNA. These adduc ts were different from those obtained with nuclease P1 enrichment of t he same. B(alpha)P was the positive control for the in vitro metabolis m, and two adduct enrichment procedures: nuclease P1 digestion and but anol extraction.