Method for selecting exposure levels for the Drosophila sex-linked recessive lethal assay

Journal Article · Thu Jan 01 04:00:00 EST 1987 · Environ. Mol. Mutagen.; (United States)

DOI:https://doi.org/10.1002/em.2850100405· OSTI ID:5605946

Thompson, E D; Reeder, B A

The use of the Drosophila sex-linked recessive lethal assay for detecting mutagenicity of chemicals is well established. When compounds are tested by feeding adult flies, the National Toxicology Program protocol specifies a 3-day feeding regimen at an exposure level that produces about 30% mortality. Uptake of the test compound is monitored by feeding behavior, amount of excretion, or abdomen size. An alternate method for determining uptake is to add radiolabeled sucrose to the feeding solution and then to determine the amount of radioactivity in the flies. We have found that the addition of radiolabeled sucrose underestimates consumption for feeding exposures longer than 24 hr because sucrose is metabolized and as much as 30% of the label is excreted, presumably as /sup 14/CO/sub 2/ or /sup 3/H/sub 2/O. Here we describe a method for determining uptake of chemicals by adding /sup 14/C-leucine to the feeding solution. The incorporation of /sup 14/c-leucine is essentially linear over the 3-day feeding period, which permits accurate estimates of food consumption. Use of this method demonstrates that lower exposure levels of a chemical that do not produce mortality actually results in higher consumption by the flies. The method is proposed as a prescreen to select the appropriate exposure level for the sex-linked recessive lethal assay.

• Research Organization: Procter and Gamble Company, Cincinnati, OH
• OSTI ID: 5605946
• Journal Information: Environ. Mol. Mutagen.; (United States), Journal Name: Environ. Mol. Mutagen.; (United States) Vol. 10:4; ISSN ENMUE
• Country of Publication: United States
• Language: English

Related Subjects

550501 -- Metabolism-- Tracer Techniques
560300* -- Chemicals Metabolism & Toxicology
59 BASIC BIOLOGICAL SCIENCES
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
AMINO ACIDS
ANIMALS
ARTHROPODS
CARBOHYDRATES
CARBON 14 COMPOUNDS
CARBOXYLIC ACIDS
DIPTERA
DISACCHARIDES
DROSOPHILA
FLIES
FOOD
FRUIT FLIES
GENES
INSECTS
INVERTEBRATES
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
LEUCINE
METABOLIC ACTIVATION
MUTAGEN SCREENING
MUTAGENS
OLIGOSACCHARIDES
ORGANIC ACIDS
ORGANIC COMPOUNDS
SACCHARIDES
SACCHAROSE
SCREENING
TRACER TECHNIQUES
TRITIUM COMPOUNDS
XENOBIOTICS