Effect of prostaglandin PGE2alpha on the synthesis of placental proteins and human placental lactogen (HPL).

The biosynthesis of placental proteins and placental lactogen (HPL) was studied in vitro in 10-12 week, 16-18 week and term human placenta in the presence and absence of PGF2alpha. The highest 14C-leucine incorporation was detected in 10 to 12 weeks old placentas of PGF2alpha to the incubation medium depressed the rate of incorporation of 14C-leucine into placental proteins in a dose dependent manner. Placentas most sensitive to this action of PGF2alpha were those obtained at 18 weeks of gestation followed by placentas at term. In vivo application of PGF2alpha for therapeutic induction of abortions resulted in the marked inhibition of placental protein synthesis in vitro.