Quantitative Aspects of the Detoxication of Naphthalene by Resistant and Susceptible House Flies1

Abstract

The rate of metabolism and excretion of naphthalene-l-C¹⁴ and 1-naphthol-1-C¹⁴ by resistant and susceptible strains of house flies, Musca domestica L., has been studied by means of injection and feeding experiments. Combustion of insects given single doses of the radioactive drugs has shown that both are rapidly eliminated; approximately 80% of an injected dose is excreted within 7 hours and 90% in 24 hours. When fed up to 0.4% 1-naphthol in sugar, the flies excrete naphthol metabolites at the rate of approximately 3 to 5 µg per day per insect. Males of both strains excrete the metabolized drug about 50% more rapidly than females. About 23 to 68% of the excreted drug is in the form of 1-naphthyl glucoside and about 8 to 17% as 1-naphthyl sulfate. Relatively more glucoside is produced by young females but the absolute amount produced by the sexes is approximately the same. Although R and S insects were compared both quantitatively and qualitatively for naphthol metabolism, no differences either in rate of metabolite production or in relative levels of metabolites could be seen.