苹果多酚对蟾蜍心脏活动的影响及其机制

Effects of apple polyphenols on cardiomotility of toads and the underlying mechanisms

目的研究苹果多酚(apple polyphenols,AP)对蟾蜍心脏活动的影响及其机制。方法采用在体心搏曲线记录法,观察AP对蟾蜍心肌收缩力和心率的影响;离体蛙心灌流法观测AP作用的剂量和时间曲线,并探讨其作用与β受体和钙内流之间的关系。结果 AP在离体和在体两个水平均能显著抑制蟾蜍心肌收缩力,而对心率没有明显影响;AP对心肌收缩力的抑制作用具有浓度和时间依赖性;AP可以部分抑制肾上腺素引起的正性肌力作用;AP对心肌收缩力的抑制作用具有钙离子依赖性。结论 AP可以显著抑制蟾蜍心肌收缩力,其作用机制可能与抑制β受体和减少钙内流有关。

Objective To investigate the direct effects of apple polyphenols(AP) on heart rates and myocardial contractility of toads.Methods In the experiment in vivo,heart beat curve of toad was recorded with the BL-420 F data acquisition and analysis system.AP or normal ringer’ s solution were given by lymph gland injection.In the experimentin vitro,isolated toad heart perfusion method w as used to observe the effect of AP on myocardial contractility.Results AP obviously depressed the myocardial contractility both in vivo and in vitro,but AP had little effects on heart rates.AP decreased the myocardial contractility in both time-and do sedependent manner.AP significantly inhibited the enhanced myocardial contractility stimulated by β-adrenal agonist or elevated calcium ions in the perfusion solution.Conclusion AP reduced the cardiac contractility of the toad in both normal condition and adrenaline stimulated condition.The effect of AP on heart was calcium-dependent,and the mechanism was concerned with the inhibition of β-adrenal receptors and the influx of calcium ions.