Mechanism of arrhythmias caused by autoantibodies against ?_1-adrenoceptors induced by hepatitis B virus in mice / 中国病理生理杂志

ABSTRACT

AIM: To investigate the significance of autoantibodies against ?_1-adrenoceptors induced by hepatitis B virus in the pathogenesis of hepatitis virus myocarditis. METHODS: 30 mice were injected peritoneally with an emulsion of hepatitis B virus and complete Freund's adjuvant every three weeks. The autoantibodies were examined by ELISA, the heart and liver specimens were collected on 56 d for pathological observation and the binding of the autoantibodies to guinea pig cardiac myocytes were examined by immunofluorescence. Using the patch clamp technique, the effects of (1∶50) autoantibodies purified by octanoic acid extraction on the action potential and L type Ca~(2+) currents of guinea pig cardiac myocytes were also investigated. RESULTS: There was a good correlation between the autoantibodies and hepatitis B virus. Without pathological changes in the heart and liver specimens, 6 mice of the test group manifested bundle branch block, sinus arrest and premature ventricular beat etc, which were positive in the autoantibodies. The specific binding of the autoantibodies of the mice to guinea pig cardiac myocytes was observed. (1∶50) autoantibodies of the mice prolonged APD_(20), APD_(50), APD_(90) by 36.46%, 29.63% and 12.40%, respectively and enhanced L type Ca~(2+) currents by (49.67?16.01)%. CONCLUSIONS: Autoantibodies against ?_1-adrenoceptors of the mice induced by hepatitis B virus result in several arrhythmias, which might be mediated by the enhancement of L type Ca~(2+) currents.