[Concentration of kininogens and low molecular kininogen antigen in plasma of pregnant rabbits and newborn progeny in health and following intravenous infusion of purified thrombin].

High levels of trypsin-releasing kinin and low molecular plasma kininogen antigen were detected in plasma of pregnant female rabbits. Respective values in plasma of their new born progeny was 2.7 times lower than that in maternal plasma. Intravenous infusion of the highly purified bovine thrombin administered to pregnant female rabbits markedly decreased plasma fibrinogen platelet count and increased fibrinogen/fibrin degradation products in blood serum. A marked decrease of trypsin-releasing kinin plasma levels accompanied these changes. No changes in the kininogen antigen levels were seen during the same experiments. Thrombin infusions administered to pregnant female rabbits did not produce measurable changes in trypsin-releasing kinin levels and plasma low molecular kininogen antigen in the progeny obtained for the investigations with the aid of cesarean section.