DNA damage and repair in vivo.

DNA damage has been implicated in carcinogenesis, mutagenesis, and aging. DNA excision repair has been implicated as an ameliorating factor for such damage. It has been proposed that there is an error-prone post-replication repair system which is both mutagenic and carcinogenic. Assay of DNA damage and repair may thus illuminate the mechanism of carcinogenesis and serve as an indicator of the carcinogenic potential of environmental agents. DNA damage induction and repair can differ in vitro and in vivo. In order to rationally evaluate environmental health effects, it is therefore important to examine DNA damage induction and repair in vivo. An in vivo method is defined here as one in which the DNA is damaged and repaired in cells in situ in the organism. In vivo methods for studying DNA adducts and excision repair, strand-breaks and strand-break repair, post-replication repair, and photoreactivation repair, and the current state of knowledge of DNA damage induction and repair in vivo, are reviewed and evaluated.