DNA and Double-Stranded Oligonucleotides - Free-Radical-Induced DNA Damage and Its Repair - page 428

Table 12 . 25. Some electron affinity relationships with nitro compounds compiled by Du-
rand and Olive (1981)

Redox dependence (b 1 /V −1 )

Property or reaction Number of studies

Mean Range

Radiosensitization 3 9.5 6.0-10.8

Reduction by
Aerobic bacteria

1 8.2

Anaerobic mammalian cells 1 10.7

Anaerobic microsomes 1 10.5

FMNH 2 1 18.4

Xanthine/xanthine oxidase 1 13.8

Cytotoxicity
Bacteria

2 101.5 11.4-11.7

Anaerobic mammalian cells 1 7.4

Aerobic mammalian cells 3 8.7 8.4-9.0

Mutagenicity
Aerobic bacteria 3 11.2 9.5-12.3

Anaerobic mammalian cells 1 7.4

DNA
Synthesis 1 12.5

Strand breakage 1 9.8

Release of Thd by reduced
nitroimidazoles

1 11

It may be mentioned that to study the effects of sensitizers on DNA radicals by
γ -irradiating biologically active DNA in aqueous solution in the presence of sen-

sitizers does not provide useful information, since under such conditions the
sensitizers scavenge • OH and thus protect rather than sensitize (Laf leur and Lo-
man 1982; for • OH-scavenging see Whillans et al. 1975).
The actual use of nitro compounds such as misonidazole in cancer treatment
is largely based on their toxicity against hypoxic cells. Here, they act as biore-