Kinetic analysis of 3beta-hydroxysteroid dehydrogenase 4-5 isomerase activity in tissue fragments from human term placenta

GENTI DE RAIMONDI SUSANA; PATRITO LUIS; FLURY ALFREDO

ELSEVIER SCIENCE INC

Año: 1983 vol. 41 p. 467 - 467

he effect of different doses of estrediol-l7(3 (E2) on the aetabo I i c pregnenolone to progesterone pathway in fragments of human term placenta incubated ip vitrq was studied. Doses considered as being physiological of 0.09 and 0.9 uM had a stimulatory effect on the conversion (p< 0,008 to O,Ol6), However, a supraphysiological &se of 45 uM showed en inhibitory activity related to the maximal stimulation (p < 0.03) A dose of 0.9 uM E favoured the accumulation of ( 3 H)-progesterone in 3 he tissue (p< 0.05). These results suggest that E2 may regulate the synthesis of progesterone in human term placenta.