The effect of some pyrimido-pyrimidine derivatives on blood coagulation and platelet aggregation.

Two pyrimido-pyrimidine derivatives, Chinoin 105 and Chinoin 123, respectively, were investigated with respect to the inhibition potency on platelet aggregation. It was shown that Chinoin 105 is a powerful inhibitor of aggregation of thrombocytes without effect on routine coagulation parameters in vitro. Chinoin 123 has a moderately inhibitory effect on the investigated reactions. An additive effect of Chinoin 105 to the inhibitory potential of PGE1 on platelet aggregation was proven.