Transport of radioactive sodium across the rat placenta in experimental toxemia of pregnancy

Abstract

The placental permeability of rats in the third trimester of pregnancy has been evaluated by determination of the radioactivity of placenta and fetus following intravenous injection of Na24Cl. Rats that were fed a vitamin E-low diet containing oxidized cod liver oil during pregnancy had a lower placental permeability to sodium ion than control animals in the fifteenth through seventeenth days of gestation. A toxic effect of the oxidized cod liver oil diet on the trophoblast is postulated as the etiology of diet-induced experimental toxemia of pregnancy. In the early stages of the development of the generalized Shwartzman reaction in pregnant rats, placental lesions have caused a severe depression in placental permeability before glomerular thrombi have impaired sodium exchange in the kidney. The alterations of placental transport effect in rats by an oxidized cod liver oil diet are similar to those which have been reported in human toxemia of pregnancy.