The dosimetry and lethal effects of maternally administered phosphorus-32 after 14 and 17 days of gestation in the rat

Pregnant female albino rats were given graded doses of radiophosphorus after 14 or 17 days of gestation and sacrificed at intervals after injection through birth. One millicurie or less of P-32 did not increase prenatal mortality after administration on either of these two days. Two millicuries produced prenatal deaths when administered after 14 days of gestation but not after I7 days; some deaths attributable to the trauma of parturition were noted in both cases. A depression of the growth curve and of birth weight was produced by doses of 0.4 mc and larger after 14 days and by doses of 0.6 mc and above after 17 days of gestation. The curves of accumulated radiation dose to the whole fetus and to various organs and systems as interpolated to one millicurie are presented and discussed. (auth)