Effect of NOS Inhibitors and Anticoagulants on Nitric Oxide Production in a Tissue-factor Induced Rat DIC Model.

Abstract

We examined the mechanism of nitric oxide (NO) production in a tissue-factor (TF)-induced disseminated intravascular coagulation (DIC) model in rats, using inducible nitric oxide synthase (iNOS) inhibitor (L-NIL), endothelial nitric oxide synthase (eNOS) inhibitor (L-NAME), Factor Xa inhibitor (DX-9065a), and thrombin inhibitor argatroban. Experimental DIC was induced by sustained infusion of 3.75 U/kg TF for 4 h via the tail vein. We then investigated the effect of these four agents on TF-induced DIC. Administration of L-NIL or L-NAME during induction of TF-induced DIC did not affect hemostatic markers, whereas elevated plasma levels of NO metabolites (NOX) were significantly suppressed by co-administration of L-NAME. A significant increase in eNOS-mRNA expression was observed in the TF-induced DIC model. Argatroban almost completely suppressed eNOS-mRNA expression. eNOS plays an important role in the NO production in the TF-induced DIC, and thrombin is a key stimulant of eNOS-mRNA expression in this model.