title: Comparative effects of protracted exposures to 60Co gamma-radiation and 239Pu alpha-radiation on breeding performance in female mice..
abstract: Breeding performances are compared of hybrid female mice given 239Pu (5 or 10 mu Cikg-1 body mass in 1% trisodium citrate via the tail-vein), or kept in a 10 rad/day or 20 rad/day 60Co gamma-irradiation field (but mated in the control area), or unirradiated. Ovarian dose-rates from the injected plutonium were initially 0.8 and 1.7 rad/day, changing little thereafter; actual gamma-ray dose-rates to breeding females averaged around 8 and 16 rad/day respectively. Both gamma-ray treatments affected reproductive performance more than the plutonium injections, with respet to duration of fertility and to offspring per litter in successive 4-weekly periods, though overall mean litter-sizes were not significantly less than controls. The r.b.e. for these effects on reproduction, attributed to germ-cell killing, is about 2.5 for the alpha-particles vs. gamma-rays, lower than for testis mass reduction in males. This low r.b.e. may be connected with inhomogeneity of alpha-particle dose within the ovary, but it is known that fission neutron versus gamma r.b.e.'s for impairment of female fertility are also lower than those for impairment of male fertility.
mesh_terms: D000512:Alpha Particles; D000818:Animals; D003037:Cobalt Radioisotopes; D005260:Female; D005720:Gamma Rays; D008098:Litter Size / Q000528:radiation effects; D008297:Male; D051379:Mice; D009865:Oocytes / Q000528:radiation effects; D011005:Plutonium / Q000494:pharmacology; D011247:Pregnancy; D012098:Reproduction / Q000528:radiation effects*; D012737:Sex Factors; D013997:Time Factors
chemical_list: D003037:Cobalt Radioisotopes; D011005:Plutonium