Effect of bisoprolol on ICa,Lin volume overload combined with pressure overload heart failure in rabbits / 西安交通大学学报(医学版)

ABSTRACT

【Objective】 To explore the effect of bisoprolol on ICa，Lin volume overload combined with pressure overload heart failure in rabbits. 【Methods】 Totally 82 male New Zealand rabbits （2.5-3.0 kg） were randomly divided into three groups： SO （sham group）， HF （heart failure group）， and BF （heart failure with bisoprolol treatment group）. HF rabbits were duplicated by aortic valve insufficiency procedure combined with abdominal aorta constriction procedure. Real-time PCR and Western blot analysis were performed to detect the expression of ICa，L in left ventricular myocytes. Left ventricular myocytes were isolated； then the cell membrane capacitance， the current density， activation and inactivation of ICa，L were recorded by whole cell patch clamp. 【Results】 ① Bisoprolol could improve the heart function of heart failure rabbits according to the measurement of echocardiography and BNP. ② The expressions of ICa，L mRNA and protein decreased significantly in heart failing rabbits （P<0.01）， but remained unaltered after chronic bisoprolol treatment （P>0.05）. ③ Membrane capacitance was larger in heart failing groups than in sham group （P<0.01）. ICa，L current density decreased greatly in HF group （P<0.01）. Bisoprolol treatment could not change Cm or ICa，L density （P>0.05）. V1/2 of activation curve negative shift enlarged window currents in heart failure groups. Bisoprolol treatment caused window currents to decrease. 【Conclusion】 Bisoprolol could reverse the heart function of heart failure rabbits and also affect the function of ICa，L.