[The source of endogenous digitalis-like substance in normal pregnancy].
OBJECTIVE
To study the source of endogenous digitialis-like substance (EDLS) which increases in maternal vein plasma during normal pregnancy.


METHODS
The EDLS concentrations in following samples: (1) villi in the 1st trimester (2) placenta, amnion and umbilical jelly of Wharton in the 3rd trimester, (3) plasma of normal non-pregnant women (4) maternal plasma in three trimesters, 24-48 hours post partum, (5) maternal plasma and umbilical blood in labour, were determined by radioimmunoassay.


RESULTS
The concentration of EDLS in villi, placenta, amnion and jelly of Wharton was about 37, 33, 29 and 24 times higher respectively than the concentration of maternal blood. There was a significant positive correlation between the concentrations of EDLS in placenta or amnion and that in jelly of Wharton. Plasma EDLS levels in pregnant women of 1st and 2nd trimesters were similar to that in non-pregnant women, while in the 3rd trimester of pregnany they were significantly increased, and then significantly decreased in 24 to 48 hours post partum. There was a significant positive correlation between the plasma EDLS level and mean arterial pressure in the 3rd trimester. The EDLS concentration in plasma of umbilical vein and artery was about 3.1 and 2.9 times higher respectively than that in the maternal plasma. There were significant positive correlations between plasma EDLS levels of umbilical vein, artery or maternal vein and the weight of placenta or newborn.


CONCLUSIONS
The fetal-placenta unit is the source of EDLS which increases in maternal vein plasma during normal pregnancy.
Gao
S
S
Kunming General Hospital, Chengdu Command of PIA.
Chen
Z
Z
Xu
Y
Y
D000328:Adult; D001794:Blood Pressure / Q000502:physiology; D002298:Cardenolides; D004077:Digoxin; D005260:Female; D006801:Humans; D011247:Pregnancy / Q000097:blood*; D012503:Saponins / Q000097:blood*; D000254:Sodium-Potassium-Exchanging ATPase / Q000037:antagonists & inhibitors*
D002298:Cardenolides; D012503:Saponins; C034504:digoxin-like factors; D004077:Digoxin; D000254:Sodium-Potassium-Exchanging ATPase