In-vivo radiotoxicity of DNA-incorporated 125I compared with that of densely ionising alpha-particles.
When the atomic nucleus of 125I decays by orbital electron capture followed by internal conversion, numerous very-low-energy electrons (Auger electrons) are emitted, so that the energy density in the immediate vicinity of the decay site is extremely high. 125I incorporated into DNA was as effective as densely ionising 5.3 MeV alpha-particles from 210Po in reducing the sperm-head population in mice. Hence the biological risks of Auger-electron emitting radionuclides widely used in biology and medicine ought to be reassessed.
Rao
D V
DV
Department of Radiology, University of Medicine and Dentistry of New Jersey, Newark.
Narra
V R
VR
Howell
R W
RW
Govelitz
G F
GF
Sastry
K S
KS
D000818:Animals; D006207:Half-Life; D007065:Idoxuridine / Q000493:pharmacokinetics / Q000633:toxicity; D007457:Iodine Radioisotopes / Q000493:pharmacokinetics / Q000633:toxicity*; D008297:Male; D051379:Mice; D011059:Polonium / Q000493:pharmacokinetics / Q000633:toxicity*; D011833:Radiation Injuries, Experimental; D011851:Radioactivity; D013091:Spermatogenesis / Q000528:radiation effects; D013737:Testis / Q000528:radiation effects*
D007457:Iodine Radioisotopes; D011059:Polonium; D007065:Idoxuridine