Caffeine enhanced measurement of mutagenesis by low levels of gamma-irradiation in human lymphocytes.
The well-known action of caffeine in synergizing mutagenesis (including chromosome aberrations) of agents like ionizing radiation by inhibition of cellular repair processes has been incorporated into a rapid procedure for detection of mutagenicity with high sensitivity. Effects of 5-10 rads of gamma-irradiation, which approximate the human lifetime dose accumulation from background radiation, can be detected in a two-day procedure using an immortalized human WBC culture. Chromosomally visible lesions are scored on cells incubated for 2 h after irradiation in the presence and absence of 1.0 mg/ml of caffeine. An eightfold amplification of scorable lesions is achieved over the action of radiation alone. This approach provides a closer approximation to absolute mutagenicity unmitigated by repair processes, which can vary in different situations. It is proposed that mutagenesis testing of this kind, using caffeine or other repair-inhibitory agents, be employed to identify mutagens in their effective concentrations to which human populations may be exposed; to detect agents such as caffeine that may synergize mutagenic actions and pose epidemiologic threats; and to discover effective anti-mutagens. Information derived from the use of such procedures may help prevent cancer and newly acquired genetic disease.
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Eleanor Roosevelt Institute for Cancer Research, Denver, Colorado 80206.
Morse
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Johnson
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Waldren
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D002110:Caffeine / Q000494:pharmacology*; D002461:Cell Line, Transformed; D002869:Chromosome Aberrations; D002877:Chromosomes, Human / Q000648:ultrastructure; D004260:DNA Repair / Q000187:drug effects; D004307:Dose-Response Relationship, Radiation; D005720:Gamma Rays; D006801:Humans; D008214:Lymphocytes / Q000187:drug effects* / Q000528:radiation effects*; D016296:Mutagenesis
D002110:Caffeine