[Correlation of progesterone and apoprotein B in pregnancy]

For the synthesis of progesterone the placenta uses cholesterol which is derived from low density lipoproteins (LDL). Apoprotein B (apo B) is the mediator for the uptake of LDL into the cell. This investigation was done to find relations between progesterone and apo B concentrations in the blood serum of pregnant women. 269 patients (8th to 41st week of pregnancy) were studied. Progesterone was estimated by radioimmunoassay, apo B by radial immunodiffusion. The concentration of apo B decreases from 8th/9th to 14th/15th week of pregnancy significantly, and this is followed by a continuous increase of the apo B concentration until parturition. The concentration of progesterone increases during pregnancy. The intermediate decrease after the 14th/15th week is to be seen in connection with the luteoplacental shift.