title: The effects of prostacyclin on the coagulation of whole blood.
abstract: The effects of prostacyclin (PGI2) on mechanical properties of forming clots were investigated by testing human blood samples on a Thrombelastograph. Concentrations greater than 50 ng/ml (blood) caused a biphasic development of clot stiffness. During the first phase, PGI2 partially inhibited the platelet involvement in coagulation causing initial clot formation at a normal time but with reduced clot stiffness. The second phase occurred after neutralization of PGI2 activity and was characterized by recovery of platelet activity to produce a final clot with normal shear modulus. The duration of the inhibitory effects depended on PGI2 concentration and hematocrit. With a normal hematocrit, a PGI2 concentration of 60 ng/ml caused an inhibition for about 40 min whereas a concentration of 100 ng/ml caused inhibition for about 75 min.
mesh_terms: D001777:Blood Coagulation / Q000187:drug effects*; D001792:Blood Platelets / Q000187:drug effects; D011464:Epoprostenol / Q000494:pharmacology*; D006400:Hematocrit; D006801:Humans; D066298:In Vitro Techniques; D013916:Thrombelastography
chemical_list: D011464:Epoprostenol