Biological assessment of chemical DNA damage in germ cells of male rabbits

Abstract

DNA damage represents a key step in mutagenesis and carcinogenesis. Excision repair has been described to be the major pathway restoring damaged DNA. Assaying DNA repair may thus illuminate the mechanism of mutagenesis and carcinogenesis and serve as an indicator of the mutagenic and carcinogenic potential of environmental chemicals and drugs. The paper demonstrates a practical application of these concepts. DNA damage induced by chemical substances in male germ cells of rabbits was assessed by the demonstration of DNA repair synthesis in meiotic and post-meiotic maturation stages. Incorporation of tritium-labeled thymidine was monitored in spermatozoa obtained by serial ejaculation. The test was validated with several standard mutagens and carcinogens, and its usefulness was demonstrated with a study on 3 suspected genotoxic drugs, i.e. hycanthone, isoniazid, and metronidazole.