Negative Inotropic Effects of ?_3-Adrenoceptor Autoantibodies from Children with Heart Failure on Isolated Cardiomyocytes of Adult Rats / 实用儿科临床杂志

ABSTRACT

Objective To explore the effects of the autoantibody against the second extracellular loop of ?3-adrenoceptor(?3AR)from children with heart failure on isolated cardiomyocytes of adult rats.Methods The synthetic peptide corresponding to the sequence of the se-cond extracellular loop(176-202 amino acid residues)of the human ?3AR was used as the antigen to screen the anti-?3AR autoantibodies from the sera of the 50 children with heart failure and 50 healthy children by enzyme linked immunosorbent assay(ELISA);IgG in the children with heart failure of positive autoantibodies sera was purified.The effects of purified IgG per each group on contractile response of isolated cardiomyocytes of adult rats were observed using motion-edge detection system and double-provocation fluorescence photomultiplier system.Results Among the 50 children with heart failure,the anti-?3AR autoantibodies positive rate was 30%(15/50 cases),and ob-viously higher than that of healthy children[12%(6/50)cases,P