FREE CHOLINE CONCENTRATION AND CEPHALIN‐N‐METHYLTRANSFERASE ACTIVITY IN THE MATERNAL AND FOETAL LIVER AND PLACENTA OF PREGNANT RATS

Abstract

1. The concentration of free choline and cephalin-N-methyltransferase activity of the maternal and foetal liver and placenta of rats in late pregnancy were determined. 2. The choline concentration of the liver fell from a mean of 130 nmol/g in adult non-pregnant rats to 38 nmol/g in late pregnancy. 3. The choline concentrations of the foetal liver and placenta had mean values of 135 and 442 nmol/g, respectively. 4. There was a significant 24% increase in the cephalin-N-methyltransferase activity of the liver during pregnancy. The enzyme activity in the foetal liver was 7% that of the maternal liver, and activity was undetectable in the placenta. 5. The results suggest that, during pregnancy, the maternal liver supplies choline to the placenta and foetal organs, like the liver, and that the demand for maternal liver choline far exceeds the supply available.