CVB3 infection induces NOS2 mRNA in hearts. Wild-type mice (MF1, 129, and MF1/129 hybrid F2) were infected with 105 or 107 pfu of CVB3. Hearts were harvested from noninfected animals (lane 1) or from infected mice at times 1, 3, 5, 7, 10, and 15 days after infection (lanes 2–7 and lanes 8–13). NOS2 expression was analyzed by Southern analysis of RT-PCR from total RNA (n = 3 mice per RT-PCR).