A mouse model of coxsackievirus myocarditis

To develop a mouse model of coxsackievirus B3 (CVB3) myocarditis. Design: Preliminary studies have indicated that mice infected with CVB3 alone erratically responded with viral myocarditis. Prospective evaluation of the effect of cyclophosphamide at two time intervals resulted in consistency for the development of myocarditis. Animals: Juvenile five- to nine-week-old male mice CD-1 type (Charles River Canada Limited). Interventions: Infection with coxsackie E3 enterovirus. Pretreatment with cyclophosphamide two days and 4 h before inoculation of 0.2 or 0.15 mg/g. Animals were killed seven, nine, 28 and 63 days post infection. Main results: Following cyclophosphamide conditioning, a tissue response infection with CVB3 was uniformly observed. Virus, however, was infrequently recovered from the myocardium whereas myocarditis became chronic after 28 days. Conclusions: Pretreatment of juvenile mice with cyclophosphamide results in a reproducible model of viral myocarditis with chronic changes in the myocardium.