Dependence of Chromium Transfer into the Rat Embryo on the Chemical Form

Abstract
The placental transfer of chromium was studied in rats using atomic absorption spectroscopy for determination of the stable isotope and scintillation counting for 51Cr. Previous findings, that simple chromium compounds injected into pregnant rats do not label the litter, were confirmed. However, appreciable concentrations of 52Cr were detected in all newborn animals. Feeding pregnant rats a diet in which a high chromium content was supplied by the natural ingredients resulted in increased chromium levels in the young, whereas giving 2 ppm chromium (as acetate) in the drinking water did not. Intragastric administration of 51Cr, incorporated into brewer's yeast, to pregnant rats led to significant labeling of the newborn. These results indicate that chromium in the form of a natural complex, but not as a simple salt, is transported across the placenta.