EFFECT OF A SELECTIVE PAF ANTAGONIST SM-10661 ((+/-)-CIS-3,5-DIMETHYL-2-(3-PYRIDYL)THIAZOLIDIN-4-ONE HCL) ON EXPERIMENTAL DISSEMINATED INTRAVASCULAR COAGULATION (DIC)

Intravenous infusion of endotoxin (0.25 mg/kg/hr for 4 hr) was shown to induce disseminated intravascular coagulation (DIC) in rats, which resulted in hypofibrinogenemia, prolongation of prothrombin (PT) and partial thromboplastin time (PTT), thrombocytopenia, and elevated levels of fibrinogen/fibrin degradation products (FDP). Oral administration (100 mg/kg) of the selective PAF antagonist, SM-10661 ((+/-)-cis-3,5-dimethyl-2-(3-pyridyl)thiazolidin-4-one HCI), counteracted the changes caused by the endotoxin. Intravenous infusion of SM-10661 (6 mg/kg bolus 2 min before endotoxin infusion + 6 mg/kg/hr for 4 hr infusion) also counteracted DIC. When suboptimal doses of gabexate mesilate, a synthetic protease inhibitor (3 mg/kg i.p.), and SM-10661 (2 mg/kg bolus + 2 mg/kg/hr for 4 hr infusion) were administered concomitantly, hematological parameters improved. The results suggest that PAF may play a role in the pathogenesis of DIC, and that together with the results already reported for other PAF antagonists, SM-10661 may be useful in the treatment of DIC.