Comparative Studies on Translocation of Ionic and Colloidal Phosphorus-32 across Placenta of Mice

Abstract

Studies on translocation of ionic and colloidal ³²P in gravid mice show that placental discrimination against the former is negligible in comparison to the latter. Ionic ³²P is deposited in fetus against a concentration gradient. An important feature of the distribution of radiophosphorus in maternal tissues is that the colloid is localized predominantly in liver with the other tissues having considerably less radionuclide burden whereas ionic ³²P is distributed more or less evenly in the tissues. The accumulation of ionic ³²P in tissues of pregnant mice is greater than in the tissues of non-pregnant mice and vice versa with respect to colloidal radiophosphorus.