title: Repair of sublethal and potentially lethal radiation damage by rat embryos exposed to gamma rays or helium lons.
abstract: Embryonic survival was examined in rats exposed to a 24-hour split-dose regimen of gamma rays or extended-Bragg-peak (EBP) helium ions on the fifth and sixth days of gestation. The data indicate that EBP helium ions, which are known to have a single-dose relative biological effectiveness (RBE) of 1.0, exhibit a split-dose RBE of 1.5 with respect to embryo killing. Using an experimental rat embryo system, delayed implantation, it was also noted that the embryocidal damage induced by EBP helium ions contains a smaller potentially lethal component than that induced by gamma rays.
mesh_terms: D000818:Animals; D001755:Blastocyst / Q000528:radiation effects; D003338:Corpus Luteum; D010065:Embryo Implantation, Delayed; D004622:Embryo, Mammalian / Q000528:radiation effects*; D004735:Energy Transfer; D005260:Female; D005333:Fetus / Q000528:radiation effects; D005720:Gamma Rays / Q000009:adverse effects; D006371:Helium / Q000009:adverse effects; D008297:Male; D011247:Pregnancy; D011829:Radiation Dosage; D011833:Radiation Injuries, Experimental; D051381:Rats
chemical_list: D006371:Helium