On the mechanism of action of 15-methyl-PGF2 alpha as an abortifacient.

Several hours following administration of long acting vaginal suppositories containing 3.0 mg of 15-methyl-PGF2 alpha for interruption of second trimester pregnancies there is an up to 10-fold increase in endogenous production of PGE2 and PGF2 alpha before abortion as reflected by gas chromatographic-mass spectrometric determination of the major plasma metabolites of PGE2 and PGF2 alpha. The data suggest that this increased formation of endogenous prostaglandins contributes to the induced uterine activity during the latter part of the abortion process.