ABSTRACT
Single doses of strontium-90 (191 μc or 382 μc) were injected intravenously to pregnant rats on the 2nd or 10th day post-conception and the developing offspring were observed for deleterious effects on the 20th day post-conception.
Injection of either dose on the 2nd day post-conception caused a significant increase in intrauterine mortality and fetal growth retardation (stunting), but a significant increase in morphological defects other than stunting was not observed.
Injection on the 10th day post-conception caused little or no increase in mortality or growth retardation following a dose of 191 μc, and only slight increases after doses of 382 μc. However, gross morphological defects of various types were observed at both dose levels, but fewer varieties of defect at the lower dose. The most common defects were, in decreasing order of frequency, taillessness, retarded growth, reduced eye volume, skeletal defects, and interscapular depression.
The radiation dose rate to both the uterus and the embryo was high soon after injection, then declined to low levels. A second peak in dose rate to the embryo occurred during late fetal life while that to the uterus remained low.
The deleterious effects observed appeared to be dependent upon the total dose of 90Sr to the dam and the gestation age at time of injection.
