Evidence for the promoting role of the intra-uterine kinin release in the development of late hypertonic saline-induced abortion.

Blood plasma kininogen (K), kininases (KS), kallikrein (KK), prekallikrein (PKK), and PGF2a were estimated in the common circulation of pregnant women during late saline-induced abortion and also in retroplacental blood after foetus delivery. The results provide evidence for intra-uterine kinin release from circulating blood K by locally activated KK from the very beginning of abortion. The greatest kinin release coincided with the strongest KS activity decrease at the time of foetus delivery. The pre-abortive KS levels correlated directly with abortus duration. Uterine PG biosynthesis was activated, but appeared to be a secondary process.