We investigated the relationship between endothelin, a potent vasoconstrictor peptide, and the pathophysiology of disseminated intravascular coagulation (DIC), using two models of DIC. Experimental DIC was induced by sustained infusion of 50 mg/kg lipopolysaccharide (LPS), or 3.75 U/kg thromboplastin, for 4 h via the rat tail vein. The effect of administration of a non-selective endothelin receptor antagonist (TAK-044) (2, 10, or 50 mg/kg, from -0.5 to 4 h) on thromboplastin-induced DIC was not significant. However, LPS-induced elevation of alanine aminotransferase, creatinine and glomerular fibrin deposition was significantly suppressed by co-administration of TAK-044 in a dose-dependent manner, although no effect of TAK-044 was observed on the platelet count, fibrinogen concentration or the level of thrombin-antithrombin complex. Moreover, plasma levels of D-dimer, which reflect the grade of fibrinolysis of cross-linked fibrin, were significantly increased by co-administration of each dose of TAK-044 in the LPS-induced DIC model in rats. Our results suggest that vasoconstriction, as well as depressed fibrinolysis, contribute to severe organ dysfunction in LPS-induced, but not thromboplastin-induced, DIC, and that endothelin plays a role in the development of organ injury in LPS-induced DIC in rats.