An inhibitor of inducible nitric oxide synthase ameliorates experimental autoimmune myocarditis in Lewis rats

We studied the effect of nitric oxide (NO) on experimental autoimmune myocarditis (EAC) in rats. We examined the role of inducible nitric oxide synthase (iNOS), an enzyme that produces NO, on hearts affected with EAC, by testing the effects of aminoguanidine (AG), a selective iNOS inhibitor, on the course of EAC. Western blotting detected iNOS in the affected cardiac tissues, but not in CFA immunized cases. Immunohistochemically, the majority of ED1 + macrophages in the EAC lesions were positive for iNOS and nitrotyrosine. A high dose of AG (200 mg/kg/day) significantly reduced the incidence of EAC ( p