EXPRESSION OF NITRIC-OXIDE SYNTHASE IN A MURINE MODEL OF VIRAL MYOCARDITIS INDUCED BY COXSACKIEVIRUS B3

Nitric oxide is known to participate in the immune and inflammatory pr ocesses. In this study, we investigated the production of nitric oxide (NO) in murine viral myocarditis induced by coxsackievirus B3. The ex pression of inducible NO synthase (iNOS) mRNA in the heart first appea red on day 4 after virus inoculation and it was detectable for one mon th by reverse transcriptase-polymerase chain reaction (RT-PCR) methods . iNOS activity which was determined by the conversion of L-[H-3] argi nine to L-[H-3]citrulline was increased on day 4 and revealed its peak on day 8. Immunohistochemistry on day 7 showed increased iNOS stainin g mainly in infiltrating macrophages and polymorphonuclear leukocytes. Thus, NO is thought to be produced in the heart and play an important role in a murine model of coxsackievirus B3-induced viral myocarditis . (C) 1996 Academic Press, Inc.