[The molecular variants of thyroxine-binding protein and the concentration of a number of hormones in the blood in the postpartum period]. / Molekuliarnye varianty tiroksinsviazyvaiushchego globulina i kontsentratsiia riada gormonov v krovi v poslerodovom periode.

The serum concentrations of the total thyroxine-binding globulin (TBGt), its pregnancy-associated molecular variant (TBG-1), thyroxine, progesterone, estradiol, and prolactin were measured by radioimmunoassay in the course of the postpartum period (0-40 days) in women. High serum TBG-1 concentrations (an average of 36% of the level observed at the time of delivery) were unexpectedly detected in the late postpartum period (days 36-40) when the concentrations of TBGt, thyroxine, estradiol and progesterone were within normal. The presence of TBG-1 in the maternal blood for a long time after delivery may be caused by estrogen-dependent synthesis and secretion rather than by its slow clearance from the blood.