ABSTRACT
Objective To evaluate the effects of β1 adrenergic receptor (β1-AR) autoantibodies on the micro-mechanics of a single rat ventricular myocyte and the concentration of intracellular calcium for investigating the pathogenic mechanism of heart disease caused by β1-AR autoantibody on both cellular and molecular levels .Methods The micro-mechanics of an acutely isolated single myocardial cell from rat was detected by using the atomic force microscopy ( AFM) in combination with laser scanning confocal micro-scope (LSCM) before and after binding to β1-AR autoantibodies.The ventricular myocyte contraction and the intracellular calcium concentration were observed as well .Results The micro-mechanics of a single ventricular myocyte was increased from (44-51) nN to (76-82) nN after binding to β1-AR autoantibodies. Its contraction frequency was also increased from (0.17±0.04) Hz to (0.40±0.03) Hz (P<0.05).More-over, the intracellular calcium fluorescence intensity was increased significantly during contraction in com -parison with that before binding to β1-AR autoantibodies [ ( 102.1 ±12.3 ) % vs ( 154.3 ±16.7 ) %, P<0.01 ] .Conclusion β1-AR autoantibody could affect the contraction and the micro-mechanics of ventricu-lar myocytes and the intracellular calcium concentration in ventricular myocytes .