Passage of strontium-90 and calcium-45 through the placenta in rats

Summary

As the results of a single intraperitoneal administration to rats of 0.4 C/gm of Ca⁴⁵ and 0.4 C/gm of Sr⁹⁰, in equilibrium with Y⁹⁰ 12 days before mating and 40 days prior to labour the passage of strontium to the fetus through the placenta during pregnancy was found to be discriminated against in favor of calcium. The extent of strontium discrimination, while from the maternal organism it reached the fetus via the placenta, was characterized by an “observed ratio” of Sr⁹⁰/Ca⁴⁵ in the organism of the newborn ratling equaling numerically 0.54±0.07. Comparative volume of strontium and calcium in the maternal skeleton during pregnancy was characterized by “observed ratios” of Sr⁹⁰±Ca⁴⁵ which by the time of birth comprised: for cranial bones 1.11±0.08, for the spine −0.97±0.08 and for the femoral bone −1.06±0.06.