Abstract:

Objective  To observe the expression of anti-cardiac myosin antibody(AMA) in mice with chronic viral myocarditis (CVMC), and to compare the interventional effects of Captopril and Oxymatrine. Methods  Balb/c mice (n=60) were infect with CVB-3 at days 0, 14,28 to establish CVMC models. The volumes of CVB-3 were 0.20, 0.25and 0.30?mL respectively. A normal control group (n=8) received an equal-volume normal saline without CVB3 at the same time. The mice that survived in the CVMC model group were randomly divided into the CVMC control group(n=8), the Captopril therapy group (n=8) and the Oxymatrine therapy group(n=8) at day 42. From then on, the Captopril therapy group and the Oxymatrine therapy group were separately treated with Captopril and Oxymatrine at a dose of 100?mg/kg, by gastric perfusion once a day for 28 days and the CVMC control group and the normal control group received an equalvolume normal saline by gastric perfusion every day, for 4 successive weeks. All mice were sacrificed at day 70. The heart was weighed and the heart weight to body weight ratio was calculated.Heart slides were separately stained with haematoxylineosin (HE) andcollagen specific Picric acid-Sirius red staining, and the collagen volume fraction (CVF) was calculated with image analysis software．The AMA (optical density value, OD value) in serum was analyzed by enzyme-linked immunosorbent assay (ELISA),and divided into two groups (the OD value ＞〖AKx-D]+2s was positive, and ＜〖AKx-D]+2s was negative). Results  Compared with the normal control group, the heartweight to body weight ratio, CVF levels and the OD value of AMA were significantly increased in the CVMC control group(all P＜0.01). Compared with the CVMC control group, the heart weight to body weight ratio, CVF levels and the OD value of AMA were significantly decreased in the Captopril therapy group and the Oxymatrine therapy group(P＜0.01, P＜0.01, P＜0.05 respectively). Compared with the AMA negative group, the heart weight to body weight ratio,CVF levels and the OD value of AMA were significantly increased in the AMA-positive group(all P＜0.01). Conclusion  Expression of AMA in serum of CVMC mice increased. Captropril and Oxymatrine may down-regulate AMA expression, and inhibit myocardial remodeling.

Key words: Chronic viral myocarditis; Anti-cardiac myosin antibody; Myocardial remodeling; Captopril; Oxymatrine;  Mice, inbred BALB C